2008 Chevrolet Silverado Owners Manual

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K-2500 Crew Cab Long Box HD (4WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,000 lbs (1 361 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,600 lbs (4 354 kg) 12,100 lbs (5 488 kg)

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C-3500 Regular Cab (2WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

10,100 lbs (4 581 kg) 12,600 lbs (5 715 kg)

C-3500 Extended Cab (2WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10
3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) 16,000 lbs (7 257 kg) 6.0L V8 (Dual Rear 18,500 lbs (8 391 kg) Wheels) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,700 lbs (4 400 kg) 12,200 lbs (5 534 kg) 9,500 lbs (4 309 kg) 12,000 lbs (5 443 kg)

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C-3500 Crew Cab (2WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10
3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) 16,000 lbs (7 257 kg) 6.0L V8 (Dual Rear Wheels) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,600 lbs (4 354 kg) 12,100 lbs (5 488 kg) 9,300 lbs (4 218 kg) 11,800 lbs (5 352 kg)

K-3500 Regular Cab (4WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10
3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) 16,000 lbs (7 257 kg) 6.0L V8 (Dual Rear Wheels) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,900 lbs (4 490 kg) 12,400 lbs (5 624 kg) 9,700 lbs (4 400 kg) 12,200 lbs (5 534 kg)

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K-3500 Extended Cab (4WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10
3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) 16,000 lbs (7 257 kg) 6.0L V8 (Dual Rear Wheels) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,500 lbs (4 309 kg) 12,000 lbs (5 443 kg) 9,200 lbs (4 173 kg) 11,700 lbs (5 307 kg)

K-3500 Crew Cab (4WD)*

Axle Ratio

Maximum Trailer Weight

GCWR**

6.0L V8

3.73
4.10
3.73
4.10

16,000 lbs (7 257 kg) 18,500 lbs (8 391 kg) 16,000 lbs (7 257 kg) 6.0L V8 (Dual Rear Wheels) 18,500 lbs (8 391 kg) *Fifth-wheel or gooseneck kingpin weight should be 15 percent to 25 percent of trailer weight up to 3,500 lbs (1 587 kg) maximum. *Trailer rating limited to 13,000 lbs (5 897 kg) with weight distributing hitch. **The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and trailer including any passengers, cargo, equipment and conversions. The GCWR for your vehicle should not be exceeded.

9,300 lbs (4 218 kg) 11,800 lbs (5 352 kg) 9,100 lbs (4 128 kg) 11,600 lbs (5 262 kg)

Ask your dealer/retailer for our trailering information or advice, or write us at our Customer Assistance Offices. See Customer Assistance Offices on page 7-5 for more information.

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Weight of the Trailer Tongue The tongue load (A) of any trailer is an important weight to measure because it affects the total or gross weight of your vehicle. The Gross Vehicle Weight (GVW) includes the curb weight of the vehicle, any cargo you may carry in it, and the people who will be riding in the vehicle. If you have a lot of options, equipment, passengers or cargo in your vehicle, it will reduce the tongue weight your vehicle can carry, which will also reduce the trailer weight your vehicle can tow. And if you will tow a trailer, you must add the tongue load to the GVW because your vehicle will be carrying that weight, too. See Loading Your Vehicle on page 4-36
for more information about your vehicle’s maximum load capacity.

The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum of 600 lbs (272 kg) for the 1500 or 2500 series, and up to a maximum of 750 lbs (340 kg) for the 2500 HD or 3500 series with a weight carrying hitch. The trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight, up to a maximum of 1,000 lbs (453 kg) for the 1500 series and up to a maximum of 1,500 lbs (680 kg) for the 2500, 2500 HD or 3500 series with a weight distributing hitch.

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Fifth wheel or gooseneck kingpin weight should be 15 to 25 percent of the trailer weight up to the maximum amount speciﬁed in the trailering chart for your vehicle. See “Weight of the Trailer”, and “Fifth-Wheel and Gooseneck Trailering” in this section. Do not exceed the maximum allowable tongue weight for your vehicle. Choose the shortest hitch extension that will position the hitch ball closest to the vehicle. This will help reduce the effect of trailer tongue weight on the rear axle. After you have loaded the trailer, weigh the trailer and then the tongue separately, to see if the weights are proper. If they are not, you may be able to get them right by moving some items around in the trailer. Trailering may be limited by the vehicle’s ability to carry tongue weight. Tongue weight cannot cause the vehicle to exceed the GVWR (Gross Vehicle Weight Rating) or the RGAWR (Rear Gross Axle Weight Rating). The effect of additional weight may reduce your trailering capacity more than the total of the additional weight.

Consider the following example: A vehicle model base weight is 5,500 lbs (2 495 kg); 2,800 lbs (1 270 kg) at the front axle and 2,700 lbs (1 225 kg) at the rear axle. It has a GVWR of 7,200 lbs (3 266 kg), a RGAWR of 4,000 lbs (1 814 kg) and a GCWR (Gross Combination Weight Rating) of 14,000 lbs (6 350 kg). The trailer rating should be:

You can expect tongue weight to be at least 10 percent of trailer weight (850 lbs (386 kg)) and because the weight is applied well behind the rear axle, the effect on the rear axle will be greater than just the weight itself, as much as 1.5 times as much. The weight at the rear axle could be 850 lbs (386 kg) X 1.5 = 1,275 lbs (578 kg). Since the rear axle already weighs 2,700 lbs (1 225 kg), adding 1,275 lbs (578 kg) brings the total to 3,975 lbs (1 803 kg). This is very close to, but within the limit for RGAWR as well. The vehicle is set to trailer up to 8,500 lbs (3 856 kg).

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But let’s say your speciﬁc vehicle is equipped with some of the latest options and you have a front seat passenger and two rear seat passengers with some luggage and gear in the vehicle as well. You may add 300 lbs (136 kg) to the front axle weight and 400 lbs (181 kg) to the rear axle weight. Your vehicle now weighs:

Weight is still below 7,200 lbs (3 266 kg) and you may think that you should subtract 700 additional pounds (318 kg) from your trailering capacity to stay within GCWR limits. Your maximum trailer would only be 7,800 lbs (3 538 kg). You may go further and think you must limit tongue weight to less than 1,000 lbs (454 kg) to avoid exceeding GVWR. But, you must still consider the effect on the rear axle. Because your rear axle now weighs 3,100 lbs (1 406 kg), you can only put 900 lbs (408 kg) on the rear axle without exceeding RGAWR.

The effect of tongue weight is about 1.5 times the actual weight. Dividing the 900 lbs (408 kg) by 1.5 leaves you with being able to handle only 600 lbs (272 kg) of tongue weight. Since tongue weight is usually at least 10 percent of total loaded trailer weight, you can expect that the largest trailer your vehicle can properly handle is 6,000 lbs (2 721 kg). It is important that you make sure your vehicle does not exceed any of its ratings — GCWR, GVWR, RGAWR, Maximum Trailer Rating or Tongue Weight. The only way to be sure you are not exceeding any of these ratings is to weigh your vehicle and trailer. Total Weight on Your Vehicle’s Tires Be sure your vehicle’s tires are inﬂated to the upper limit for cold tires. You’ll ﬁnd these numbers on the Certiﬁcation label at the rear edge of the driver’s door or see Loading Your Vehicle for more information. Then be sure you don’t go over the GVW limit for your vehicle, or the GAWR, including the weight of the trailer tongue. If you use a weight distributing hitch, make sure you don’t go over the rear axle limit before you apply the weight distribution spring bars.

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Hitches It’s important to have the correct hitch equipment. Crosswinds, large trucks going by and rough roads are a few reasons why you’ll need the right hitch. Weight-Distributing Hitches and Weight Carrying Hitches

A: Body to Ground Distance

B: Front of Vehicle

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When using a weight-distributing hitch, the hitch must be adjusted so the distance (A) remains the same both before and after coupling the trailer to the tow vehicle. If you use a step-bumper hitch, the bumper could be damaged in sharp turns. Make sure there is ample room when turning to avoid contact between the trailer and the bumper. If you will be pulling a trailer that, when loaded, will weigh more than 5,000 lbs (2 270 kg) be sure to use a properly mounted weight-distributing hitch and sway control of the proper size. This equipment is very important for proper vehicle loading and good handling when driving. Always use a sway control if the trailer will weigh more than these limits. You can ask a hitch dealer about sway controls. Fifth Wheel and Gooseneck Trailering Fifth wheel and gooseneck trailers can be used with many pickup models. These trailers place a larger percentage of the weight (kingpin weight) on the tow vehicle than conventional trailers. Make sure this weight does not cause the vehicle to exceed GAWR or GVWR. Fifth wheel or gooseneck kingpin weight should be 15 to 25 percent of the trailer weight up to the maximum amount speciﬁed in the trailering chart for your vehicle. See “Weight of the Trailer” in this section for more information.

The hitch should be located in the pickup bed so that it’s centerline is over or slightly in front of the rear axle. Take care that it is not so far forward that it will contact the back of the cab in sharp turns. This is especially important for short box pickups. Trailer pin box extensions and sliding ﬁfth wheel hitch assemblies can help this condition. There should be at least six inches of clearance between the top of the pickup box and the bottom of the trailer shelf that extends over the box. Make sure the hitch is attached to the tow vehicle frame rails. Do not use the pickup box for support. Safety Chains You should always attach chains between your vehicle and your trailer. Cross the safety chains under the tongue of the trailer to help prevent the tongue from contacting the road if it becomes separated from the hitch. Instructions about safety chains may be provided by the hitch manufacturer or by the trailer manufacturer. If you are towing a trailer up to 5,000 lbs (2 271 kg) with a factory-installed step bumper, you may attach the safety chains to the attaching points on the bumper. If you are towing a trailer up to your vehicle’s trailer rating limit you may attach the safety chains to the attaching point on the hitch platform. If you are towing with an aftermarket hitch follow the trailer or hitch manufacturer’s recommendation for attaching safety chains. Always leave just enough slack so you can turn with your rig. Never allow safety chains to drag on the ground.

Trailer Brakes If your trailer weighs more than 2,000 lbs (900 kg) loaded, then it needs its own brakes – and they must be adequate. Be sure to read and follow the instructions for the trailer brakes so you’ll be able to install, adjust and maintain them properly. If your vehicle is equipped with StabiliTrak®, your trailer cannot tap into the vehicle’s hydraulic brake system. Your trailer brake system can tap into the vehicle’s hydraulic brake system only if: (cid:127) The trailer parts can withstand 3,000 psi

(20 650 kPa) of pressure.

(cid:127) The trailer’s brake system will use less than

0.02 cubic inch (0.3 cc) of ﬂuid from your vehicle’s master cylinder. Otherwise, both braking systems won’t work well. You could even lose your brakes. If everything checks out this far, make the brake tap at the port on the master cylinder that sends the ﬂuid to the rear brakes. But don’t use copper tubing for this. If you do, it will bend and ﬁnally break off. Use steel brake tubing.

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Integrated Trailer Brake Control System

Your vehicle may have an Integrated Trailer Brake Control (ITBC) system for electric trailer brakes.

This symbol is located on the Trailer Brake Control Panel on vehicles with an Integrated Trailer Brake Control System. The power output to the trailer brakes is based on the amount of brake pressure being applied by your vehicle’s brake system. This available power output to the trailer brakes can be adjusted to a wide range of trailering situations.

The ITBC system is integrated with your vehicle’s brake, anti-lock brake and StabiliTrak (if equipped) systems. In trailering conditions that cause your vehicle’s anti-lock brake or StabiliTrak systems to activate, power sent to the trailer’s brakes will be automatically adjusted to minimize trailer wheel lock-up. This does not imply that your trailer has the StabiliTrak system. If your vehicle’s brake, anti-lock brake or StabiliTrak systems are not functioning properly, your ITBC system may not be fully functional or may not function at all. Make sure all of these systems are fully operational to ensure full functionality of the ITBC system. The ITBC system is powered through your vehicle’s electrical system. Turning the ignition off will also turn off the ITBC system. The ITBC system is fully functional only when the ignition is in ON or in RUN. The ITBC system can only be used with trailers with electric brakes.

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{CAUTION:

Connecting a trailer that is not compatible with the ITBC system may result in reduced or complete loss of trailer braking. There may be an increase in stopping distance or trailer instability which could result in personal injury or damage to your vehicle, trailer, or other property. An aftermarket controller may be available for use with trailers with surge, air or electric-over-hydraulic trailer brake systems. To determine the type of brakes on your trailer and the availability of controllers, check with your trailer manufacturer or dealer.

When trailering, make sure of the following: (cid:127) The ITBC system is used only with trailers that are

equipped with electric brakes.

(cid:127) All applicable local and federal laws and regulations

are followed.

(cid:127) All electrical and mechanical connections to the

trailer are made correctly.

(cid:127) The trailer’s brakes are in proper working condition. (cid:127) The trailer and vehicle are properly loaded for

the towing condition.

The ITBC system is a factory installed item. Out-of-factory installation of this system should not be attempted. GM is not responsible for warranty or performance of the system resulting from out-of-factory installation.

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The ITBC system has a control panel located on the instrument panel to the left of the steering column. See Instrument Panel Overview (Base/Uplevel version) on page 3-4 or Instrument Panel Overview (Premium version) on page 3-6 for more information on location. The control panel allows you to adjust the amount of output, referred to as trailer gain, available to the electric trailer brakes and allows you to manually apply the trailer brakes. The Trailer Brake Control Panel is used along with the Trailer Brake Display Page on the DIC to adjust and display power output to the trailer brakes. Trailer Brake DIC Display Page The ITBC system displays messages into the vehicle’s Driver Information Center (DIC). See DIC Warnings and Messages on page 3-66 for more information.

Trailer Brake Control Panel

A. Manual Trailer Brake Apply Lever B. Trailer Gain Adjustment Buttons

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The display page indicates Trailer Gain setting, power output to the electric trailer brakes, trailer connection and system operational status.

A. Trailer Gain Setting B. Power Output to Trailer Brakes C. No trailer with electric brakes connected or fault

present

The Trailer Brake Display Page can be displayed by performing any of the following actions: (cid:127) Scrolling through the DIC menu pages using the odometer trip stem or the DIC Vehicle Information button (if equipped).

(cid:127) Pressing a Trailer Gain button – If the Trailer Brake Display Page is not currently displayed, pressing a Trailer Gain button will ﬁrst recall the current Trailer Gain setting. After the Trailer Brake Display Page is displayed, subsequent depressions of the gain buttons will then cause the Trailer Gain setting to change.

(cid:127) Activating the Manual Trailer Brake Apply lever. (cid:127) Connecting a trailer equipped with electric

trailer brakes.

All DIC warning and service messages must ﬁrst be acknowledged by the driver before the Trailer Brake Display Page can be displayed and Trailer Gain can be adjusted.

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(cid:127) There is a fault present in the wiring to the electric

trailer brakes (a CHECK TRAILER WIRING message will also be displayed on the DIC).

(cid:127) There is a fault in the ITBC system (a SERVICE

TRAILER BRAKE SYSTEM message will also be displayed in the DIC).

Manual Trailer Brake Apply The Manual Trailer Brake Apply Lever is located on the Trailer Brake Control Panel and is used to apply the trailer’s electric brakes independent of your vehicle’s brakes. This lever is used in the Trailer Gain Adjustment Procedure to properly adjust the power output to the trailer brakes. Sliding the lever to the left will apply only the trailer brakes. The power output to the trailer is indicated in the Trailer Brake Display Page in the DIC. If your vehicle’s service brakes are applied while using the Manual Trailer Brake Apply Lever, the trailer output power will be the greater of the two. The trailer and the vehicle’s brake lamps will come on when either vehicle braking or manual trailer brakes are applied.

TRAILER GAIN – This setting is displayed anytime the Trailer Brake Display Page is active. This setting can be adjusted from 0.0 to 10.0 with either a trailer connected or disconnected. To adjust the Trailer Gain, press one of the Trailer Gain adjustment buttons located on the Trailer Brake Control Panel. Press and hold a gain button to cause the Trailer Gain to continuously adjust. To turn the output to the trailer off, adjust the Trailer Gain setting to 0.0 (zero). 0.0 (zero) gain is the factory default setting. To properly adjust trailer gain, see the Trailer Gain Adjustment Procedure later in this section. TRAILER OUTPUT – This is displayed any time a trailer with electric brakes is connected. Output to the electric brakes is based on the amount of vehicle braking present and relative to the Trailer Gain setting. Output is displayed from 0 to 10 bars for each gain setting. The Trailer Output will indicate “- - - - - -“ on the Trailer Brake Display Page whenever the following occur: (cid:127) No trailer is connected. (cid:127) A trailer without electric brakes is connected (no

DIC message is displayed).

(cid:127) A trailer with electric brakes has become

disconnected (a CHECK TRAILER WIRING message will also be displayed on the DIC).

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Trailer Gain Adjustment Procedure Trailer Gain should be set for a speciﬁc trailering condition and must be adjusted any time vehicle loading, trailer loading or road surface conditions change. Setting the Trailer Gain properly is needed for the best trailer stopping performance. A trailer that is over-gained may result in locked trailer brakes. A trailer that is under-gained may result in not enough trailer braking. Both of these conditions may result in poorer stopping and stability of the vehicle and trailer. Use the following procedure to correctly adjust Trailer Gain for each towing condition: 1. Make sure the trailer brakes are in proper working

condition.

2. Connect a properly loaded trailer to the vehicle and

make all necessary mechanical and electrical connections. See Loading Your Vehicle on page 4-36 for more information.

3. After the electrical connection is made to a trailer

equipped with electric brakes: (cid:127) A TRAILER CONNECTED message will be

brieﬂy displayed on the DIC display.

(cid:127) The Trailer Brake Display Page will appear on the DIC showing TRAILER GAIN and TRAILER OUTPUT.

(cid:127) In the Trailer Output display on the DIC, “- - - - - -“

will disappear if there is no error present. Connecting a trailer without electric brakes will not clear the six dashed lines.

4. Adjust the Trailer Gain by using the gain adjustment

(+ / -) buttons on the Trailer Brake Control Panel.

5. Drive the vehicle with the trailer attached on a level road surface representative of the towing condition and free of traffic at about 20 to 25 mph (32 to 40 km/h) and fully apply the Manual Trailer Brake Apply lever. Adjusting trailer gain at speeds lower than 20 to 25 mph (32 to 40 km/h) may result in an incorrect gain setting.

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6. Adjust the Trailer Gain to just below the point of

trailer wheel lock-up, indicated by trailer wheel squeal or puffs of tire smoke when a trailer wheel locks. Trailer wheel lock-up may not occur if towing a heavily loaded trailer. In this case, adjust the Trailer Gain to the highest allowable setting for the towing condition.

7. Re-adjust Trailer Gain any time vehicle loading, trailer loading or road surface conditions change or if you notice trailer wheel lock-up at any time while you are towing.

Other ITBC Related DIC Messages In addition to displaying TRAILER GAIN and TRAILER OUTPUT through the DIC, trailer connection and ITBC system status is displayed in the DIC. TRAILER CONNECTED – This message will be brieﬂy displayed when a trailer with electric brakes is ﬁrst connected to the vehicle. This message will automatically turn off in about ten seconds. The driver can also acknowledge this message before it automatically turns off.

CHECK TRAILER WIRING – This message will be displayed if: 1. The ITBC system ﬁrst determines connection to a

trailer with electric brakes and then the trailer harness becomes disconnected from the vehicle. If the disconnect occurs while the vehicle is stationary, this message will automatically turn off in about thirty seconds. This message will also turn off if the driver acknowledges this message off or if the trailer harness is re-connected. If the disconnect occurs while the vehicle is moving, this message will continue until the ignition is turned off. This message will also turn off if the driver acknowledges this message off or if the trailer harness is re-connected.

2. There is an electrical fault in the wiring to the

electric trailer brakes. This message will continue as long as there is an electrical fault in the trailer wiring. This message will also turn off if the driver acknowledges this message off.

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To determine if the electrical fault is on the vehicle side or trailer side of the trailer wiring harness connection, do the following: 1. Disconnect the trailer wiring harness from the

vehicle.

2. Turn the ignition OFF. 3. Wait ten seconds, then turn the ignition back

to RUN.

4. If the CHECK TRAILER WIRING message

re-appears, the electrical fault is on the vehicle side. If the CHECK TRAILER WIRING message only re-appears when you connect the trailer wiring harness to the vehicle, the electrical fault is on the trailer side.

SERVICE TRAILER BRAKE SYSTEM – This message will be displayed when there is a problem with the ITBC system. If this message persists over multiple ignition cycles there is problem with the ITBC system. Take your vehicle to an authorized GM dealer to have the ITBC system diagnosed and repaired.

If either the CHECK TRAILER WIRING or SERVICE TRAILER BRAKE SYSTEM message is displayed while you are driving your vehicle, you no longer have power available to your trailer brakes. When traffic conditions allow, carefully pull your vehicle over to the side of the road and turn the ignition off. Check the wiring connection to the trailer and turn the ignition back on. If either of these messages continues, either your vehicle or your trailer needs service. An authorized GM dealer may be able to diagnose and repair problems with your trailer. However, any diagnosis and repair of your trailer is not covered under your GM Warranty. Please contact your trailer dealer for assistance with trailer repairs and trailer warranty information.

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Driving with a Trailer

{CAUTION:

If you have a rear-most window open and you pull a trailer with your vehicle, carbon monoxide (CO) could come into your vehicle. You cannot see or smell CO. It can cause unconsciousness or death. See Engine Exhaust on page 2-54. To maximize your safety when towing a trailer: (cid:127) Have your exhaust system inspected for leaks, and make necessary repairs before starting on your trip.

(cid:127) Keep the rear-most windows closed.

CAUTION:

(Continued)

CAUTION:

(Continued)

(cid:127) If exhaust does come into your vehicle through a window in the rear or another opening, drive with your front, main heating or cooling system on and with the fan on any speed. This will bring fresh, outside air into your vehicle. Do not use the climate control setting for maximum air because it only recirculates the air inside your vehicle. See Climate Control System (With Air Conditioning ) on page 3-25 or Climate Control System (Heater Only) on page 3-28.

Towing a trailer requires a certain amount of experience. Before setting out for the open road, you’ll want to get to know your rig. Acquaint yourself with the feel of handling and braking with the added weight of the trailer. And always keep in mind that the vehicle you are driving is now a good deal longer and not nearly as responsive as your vehicle is by itself.

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Before you start, check all trailer hitch parts and attachments, safety chains, electrical connector, lamps, tires and mirror adjustment. If the trailer has electric brakes, start your vehicle and trailer moving and then apply the trailer brake controller by hand to be sure the brakes are working. This lets you check your electrical connection at the same time. During your trip, check occasionally to be sure that the load is secure, and that the lamps and any trailer brakes are still working. While towing a trailer or when exposed to long periods of sunshine, the ﬂoor of the truck bed may become very warm. Avoid putting items in the truck bed that might be affected by high ambient temperatures. Following Distance Stay at least twice as far behind the vehicle ahead as you would when driving your vehicle without a trailer. This can help you avoid situations that require heavy braking and sudden turns.

Passing You’ll need more passing distance up ahead when you’re towing a trailer. And, because you’re a good deal longer, you’ll need to go much farther beyond the passed vehicle before you can return to your lane. Backing Up Hold the bottom of the steering wheel with one hand. Then, to move the trailer to the left, just move that hand to the left. To move the trailer to the right, move your hand to the right. Always back up slowly and, if possible, have someone guide you. Making Turns Notice: Making very sharp turns while trailering could cause the trailer to come in contact with the vehicle. Your vehicle could be damaged. Avoid making very sharp turns while trailering. When you’re turning with a trailer, make wider turns than normal. Do this so your trailer won’t strike soft shoulders, curbs, road signs, trees or other objects. Avoid jerky or sudden maneuvers. Signal well in advance.

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Turn Signals When Towing a Trailer The arrows on your instrument panel will ﬂash whenever you signal a turn or lane change. Properly hooked up, the trailer lamps will also ﬂash, telling other drivers you’re about to turn, change lanes or stop. When towing a trailer, the arrows on your instrument panel will ﬂash for turns even if the bulbs on the trailer are burned out. Thus, you may think drivers behind you are seeing your signal when they are not. It’s important to check occasionally to be sure the trailer bulbs are still working. Driving On Grades Reduce speed and shift to a lower gear before you start down a long or steep downgrade. If you don’t shift down, you might have to use your brakes so much that they would get hot and no longer work well.

You can tow in DRIVE (D). You may want to shift the transmission to lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). You may also want to activate the tow/haul mode if the transmission shifts too often. See “Tow/Haul Mode” later in this section. When towing at high elevation on steep uphill grades, consider the following: Engine coolant at higher elevations will boil at a lower temperature than at or near sea level. If you turn your engine off immediately after towing at high elevation on steep uphill grades, your vehicle may show signs similar to engine overheating. To avoid this, let the engine run while parked, preferably on level ground, with the transmission in PARK (P) at least ﬁve minutes before turning the engine off. If you do get the overheat warning, see Engine Overheating on page 5-32.

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Parking on Hills

{CAUTION:

You really should not park your vehicle, with a trailer attached, on a hill. If something goes wrong, your rig could start to move. People can be injured, and both your vehicle and the trailer can be damaged.

But if you ever have to park your rig on a hill, here’s how to do it: 1. Apply your regular brakes, but don’t shift into

PARK (P) yet.

2. Have someone place chocks under the trailer

wheels.

3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.

4. Reapply the regular brakes. Then apply your

parking brake and shift into PARK (P).

5. If you have a four-wheel-drive vehicle, be sure the

transfer case is in a drive gear and not in NEUTRAL.

6. Release the regular brakes.

{CAUTION:

It can be dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) with the parking brake ﬁrmly set. Your vehicle can roll. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle will not move, even when you are on fairly level ground, use the steps that follow. Always put the shift lever fully in PARK (P) with the parking brake ﬁrmly set. If the transfer case on four-wheel-drive vehicles is in NEUTRAL, your vehicle will be free to roll, even if your shift lever is in PARK (P). So, be sure the transfer case is in a drive gear — not in NEUTRAL.

4-89

Trailer Wiring Harness Your vehicle is equipped with one of the following wiring harnesses for towing a trailer or hauling a slide-in camper. Basic Trailer Wiring All regular, extended cab and crew cab pickups have a seven-wire trailer towing harness. For vehicles not equipped with heavy duty trailering, the harness is clipped to the vehicle’s frame behind the spare tire mount. The harness requires the installation of a trailer connector, which is available through your dealer. If you need to tow a light-duty trailer with a standard four-way round pin connector, you can also get an adapter from your dealer.

When You Are Ready to Leave After Parking on a Hill 1. Apply your regular brakes and hold the pedal down

while you: (cid:127) Start your engine (cid:127) Shift into a gear (cid:127) Release the parking brake

2. Let up on the brake pedal. 3. Drive slowly until the trailer is clear of the chocks. 4. Stop and have someone pick up and store the

chocks.

Maintenance When Trailer Towing Your vehicle will need service more often when you’re pulling a trailer. See Scheduled Maintenance (Gasoline Engine) on page 6-4 for more information. Things that are especially important in trailer operation are automatic transmission ﬂuid (don’t overﬁll), engine oil, axle lubricant, belt, cooling system and brake system. Each of these is covered in this manual, and the Index will help you ﬁnd them quickly. If you’re trailering, it’s a good idea to review these sections before you start your trip. Check periodically to see that all hitch nuts and bolts are tight.

4-90

Heavy-Duty Trailer Wiring Harness Package

For vehicles equipped with heavy duty trailering, the harness is connected to a bracket on the hitch platform. The seven-wire harness contains the following trailer circuits: (cid:127) Yellow: Left Stop/Turn Signal (cid:127) Dark Green: Right Stop/Turn Signal (cid:127) Brown: Taillamps (cid:127) White: Ground (cid:127) Light Green: Back-up Lamps (cid:127) Red: Battery Feed* (cid:127) Dark Blue: Trailer Brake*

*The fuses for these two circuits are installed in the underhood electrical center, but the wires are not connected. They should be connected by your dealer or a qualiﬁed service center. The fuse and wire for the ITBC is factory installed and connected if the vehicle is equipped with an ITBC. The fuse for the battery feed is not required if your vehicle has an auxiliary battery. If your vehicle does not have an auxiliary battery, have your dealer or authorized service center install the required fuse. If you are charging a remote (non-vehicle) battery, press the tow/haul mode button located at the end of the shift lever. This will boost the vehicle system voltage and properly charge the battery. If the trailer is too light for tow/haul mode, you can turn on the headlamps as a second way to boost the vehicle system and charge the battery.

4-91

Camper/Fifth-Wheel Trailer Wiring Package The seven-wire camper harness is located under the front edge of the pickup box on the driver’s side of the vehicle, attached to the frame bracket. A connector will have to be added to the wiring harness which connects to the camper. The harness contains the following camper/trailer circuits: (cid:127) Yellow: Left Stop/Turn Signal (cid:127) Dark Green: Right Stop/Turn Signal (cid:127) Brown: Taillamps (cid:127) White: Ground (cid:127) Light Green: Back-up Lamps (cid:127) Red: Battery Feed (cid:127) Dark Blue: Trailer Brake

4-92

If your vehicle is equipped with the “Heavy-Duty Trailering” option, please refer to “Heavy-Duty Trailer Wiring Package” earlier in this section. When the camper-wiring harness is ordered without the heavy-duty trailering package, an eight-wire harness with a seven-pin connector is located at the rear of the vehicle and is tied to the vehicle’s frame.

Electric Brake Control Wiring Provisions These wiring provisions are included with your vehicle as part of the trailer wiring package. These provisions are for an electric brake controller. The instrument panel contains blunt cut wires near the data link connector for the trailer brake controller. The harness contains the following wires: (cid:127) Dark Blue: Brake Signal to Trailer Connector (cid:127) Red/Black: Battery (cid:127) Light Blue/White: Brake Switch (cid:127) White: Ground It should be installed by your dealer or a qualiﬁed service center. If your vehicle is equipped with an ITBC, the blunt cuts exist, but are not connected further in the harness. If you install an aftermarket trailer brake controller, the ITBC must be disconnected. Do not power both ITBC and aftermarket controllers to control the trailer brakes at the same time.

Auxiliary Battery The auxiliary battery provision can be used to supply electrical power to additional equipment that you may choose to add, such as a slide-in camper. If your vehicle has this provision, this relay will be located on the driver’s side of the vehicle, next to the underhood electrical center. Be sure to follow the proper installation instructions that are included with any electrical equipment that you install. Notice: Leaving electrical equipment on for extended periods will drain the battery. Always turn off electrical equipment when not in use and do not use equipment that exceeds the maximum amperage rating for the auxiliary battery provision.

Trailer Recommendations You must subtract your hitch loads from the CWR for your vehicle. Weigh your vehicle with the trailer attached, so that you won’t go over the GVWR or GAWR. If you are using a weight-distributing hitch, weigh the vehicle without the spring bars in place. You’ll get the best performance if you spread out the weight of your load the right way, and if you choose the correct hitch and trailer brakes. For more information, see Towing a Trailer on page 4-55.

4-93

✍ NOTES

4-94

Section 5

Service and Appearance Care

Service ............................................................5-4
Accessories and Modiﬁcations ..........................5-4
California Proposition 65 Warning .....................5-4
California Perchlorate Materials Requirements .....5-5
Doing Your Own Service Work .........................5-5
Adding Equipment to the Outside of

Your Vehicle ..............................................5-5
Fuel ................................................................5-6
Gasoline Octane ............................................5-6
Gasoline Speciﬁcations ....................................5-6
California Fuel ...............................................5-7
Additives .......................................................5-7
Fuel E85 (85% Ethanol) ..................................5-8
Fuels in Foreign Countries ...............................5-9
Filling the Tank ............................................5-10
Filling a Portable Fuel Container .....................5-12
Checking Things Under the Hood ....................5-12
Hood Release ..............................................5-13
Engine Compartment Overview .......................5-14
Engine Oil (Gasoline Engine) ..........................5-15
Engine Oil Life System ..................................5-18
Engine Air Cleaner/Filter (Gasoline Engines) .....5-20
Automatic Transmission Fluid

(6-Speed Transmission) ..............................5-22

Automatic Transmission Fluid

(4-Speed Transmission) ..............................5-26
Engine Coolant .............................................5-29
Coolant Surge Tank Pressure Cap ..................5-32
Engine Overheating .......................................5-32
Overheated Engine Protection

Operating Mode (V8 Engines Only) ..............5-34
Cooling System ............................................5-35
Engine Fan Noise .........................................5-40
Power Steering Fluid .....................................5-41
Windshield Washer Fluid ................................5-42
Brakes ........................................................5-43
Battery ........................................................5-46
Jump Starting ...............................................5-47
Rear Axle .......................................................5-52
Four-Wheel Drive ............................................5-54
Front Axle ......................................................5-56
Noise Control System .....................................5-57

Tampering with Noise Control System

Prohibited .................................................5-57
Headlamp Aiming ...........................................5-58

5-1

Section 5

Service and Appearance Care

Bulb Replacement ..........................................5-61
Halogen Bulbs ..............................................5-61
Headlamps ..................................................5-62
Center High-Mounted Stoplamp (CHMSL) and

Cargo Lamp .............................................5-63

Pickup Box Identiﬁcation and

Fender Marker Lamps ................................5-64

Taillamps, Turn Signal, Stoplamps and

Back-up Lamps .........................................5-64
License Plate Lamp ......................................5-66
Replacement Bulbs .......................................5-66
Windshield Wiper Blade Replacement ..............5-67
Tires ..............................................................5-68
Tire Sidewall Labeling ...................................5-69
Tire Terminology and Deﬁnitions .....................5-73
Inﬂation - Tire Pressure .................................5-76
Dual Tire Operation .......................................5-77
Tire Pressure Monitor System .........................5-78
Tire Pressure Monitor Operation .....................5-79
Tire Inspection and Rotation ...........................5-83
When It Is Time for New Tires .......................5-86
Buying New Tires .........................................5-86
Different Size Tires and Wheels ......................5-88
Uniform Tire Quality Grading ..........................5-89

Wheel Alignment and Tire Balance ..................5-90
Wheel Replacement ......................................5-90
Tire Chains ..................................................5-92
If a Tire Goes Flat ........................................5-93
Changing a Flat Tire .....................................5-94
Removing the Spare Tire and Tools ................5-95
Removing the Flat Tire and Installing the

Spare Tire ..............................................5-100
Secondary Latch System ..............................5-106
Storing a Flat or Spare Tire and Tools ...........5-110
Spare Tire .................................................5-113
Appearance Care ..........................................5-114
Interior Cleaning .........................................5-114
Fabric/Carpet ..............................................5-115
Leather ......................................................5-116
Instrument Panel, Vinyl, and Other Plastic

Surfaces .................................................5-117
Care of Safety Belts ....................................5-117
Weatherstrips .............................................5-117
Washing Your Vehicle ..................................5-118
Cleaning Exterior Lamps/Lenses ....................5-118
Finish Care ................................................5-119
Windshield and Wiper Blades .......................5-120
Aluminum or Chrome-Plated Wheels

and Trim ................................................5-120

5-2

Section 5

Service and Appearance Care

Tires .........................................................5-121
Sheet Metal Damage ...................................5-121
Finish Damage ...........................................5-122
Underbody Maintenance ...............................5-122
Chemical Paint Spotting ...............................5-122
Vehicle Care/Appearance Materials ................5-123
Vehicle Identiﬁcation .....................................5-124
Vehicle Identiﬁcation Number (VIN) ................5-124
Service Parts Identiﬁcation Label ...................5-124

Electrical System ..........................................5-125
Add-On Electrical Equipment .........................5-125
Windshield Wiper Fuses ...............................5-125
Power Windows and Other Power Options ......5-125
Fuses and Circuit Breakers ..........................5-125
Instrument Panel Fuse Block ........................5-126
Center Instrument Panel Fuse Block ..............5-128
Underhood Fuse Block ................................5-129
Capacities and Speciﬁcations ........................5-133

5-3

Service For service and parts needs, visit your dealer/retailer. You will receive genuine GM parts and GM-trained and supported service people. Genuine GM parts have one of these marks:

5-4

Accessories and Modiﬁcations When non-dealer/non-retailer accessories are added to your vehicle they can affect your vehicle’s performance and safety, including such things as, airbags, braking, stability, ride and handling, emissions systems, aerodynamics, durability, and electronic systems like antilock brakes, traction control and stability control. Some of these accessories could even cause malfunction or damage not covered by warranty. GM Accessories are designed to complement and function with other systems on your vehicle. Your GM dealer/retailer can accessorize your vehicle using genuine GM Accessories. When you go to your GM dealer/retailer and ask for GM Accessories, you will know that GM-trained and supported service technicians will perform the work using genuine GM Accessories. Also, see Adding Equipment to Your Airbag-Equipped Vehicle on page 1-86.

California Proposition 65 Warning Most motor vehicles, including this one, contain and/or emit chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Engine exhaust, many parts and systems (including some inside the vehicle), many ﬂuids, and some component wear by-products contain and/or emit these chemicals.

California Perchlorate Materials Requirements Certain types of automotive applications, such as airbag initiators, seat belt pretensioners, and lithium batteries contained in remote keyless entry transmitters, may contain perchlorate materials. Special handling may be necessary. For additional information, see www.dtsc.ca.gov/hazardouswaste/perchlorate.

Doing Your Own Service Work

{CAUTION:

You can be injured and your vehicle could be damaged if you try to do service work on a vehicle without knowing enough about it.

(cid:127) Be sure you have sufficient knowledge,

experience, the proper replacement parts, and tools before you attempt any vehicle maintenance task.

(cid:127) Be sure to use the proper nuts, bolts,

and other fasteners. English and metric fasteners can be easily confused. If you use the wrong fasteners, parts can later break or fall off. You could be hurt.

If you want to do some of your own service work, you should use the proper service manual. It tells you much more about how to service your vehicle than this manual can. To order the proper service manual, see Service Publications Ordering Information on page 7-15. Your vehicle has an airbag system. Before attempting to do your own service work, see Servicing Your Airbag-Equipped Vehicle on page 1-86. You should keep a record with all parts receipts and list the mileage and the date of any service work you perform. See Maintenance Record on page 6-18.

Adding Equipment to the Outside of Your Vehicle Things you might add to the outside of your vehicle can affect the airﬂow around it. This can cause wind noise and can affect fuel economy and windshield washer performance. Check with your dealer/retailer before adding equipment to the outside of your vehicle.

5-5

Gasoline Octane Use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

Gasoline Speciﬁcations At a minimum, gasoline should meet ASTM speciﬁcation D 4814 in the United States or CAN/CGSB-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT). We recommend against the use of gasolines containing MMT. See Additives on page 5-7 for additional information.

Fuel If your vehicle has a diesel engine, see “Diesel Fuel Requirements and Fuel System” in the DURAMAX® Diesel manual. For vehicles with gasoline engines, please read this. Gasoline Use of the recommended fuel is an important part of the proper maintenance of your vehicle. To help keep the engine clean and maintain optimum vehicle performance, we recommend the use of gasoline advertised as TOP TIER Detergent Gasoline. The 8th digit of the Vehicle Identiﬁcation Number (VIN) shows the code letter or number that identiﬁes your vehicle’s engine. The VIN is at the top left of the instrument panel. See Vehicle Identiﬁcation Number (VIN) on page 5-124. If your vehicle has the 5.3L V8 engine (VIN Code 0) or the 5.3L V8 engine (VIN Code 3), you can use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85); also see Fuel E85 (85% Ethanol) on page 5-8. In all other gasoline engines, use only regular unleaded gasoline.

5-6

California Fuel If your vehicle is certiﬁed to meet California Emissions Standards, it is designed to operate on fuels that meet California speciﬁcations. See the underhood emission control label. If this fuel is not available in states adopting California emissions standards, your vehicle will operate satisfactorily on fuels meeting federal speciﬁcations, but emission control system performance might be affected. The malfunction indicator lamp could turn on and your vehicle might fail a smog-check test. See Malfunction Indicator Lamp on page 3-49. If this occurs, return to your authorized dealer/retailer for diagnosis. If it is determined that the condition is caused by the type of fuel used, repairs might not be covered by the vehicle warranty.

Additives To provide cleaner air, all gasolines in the United States are now required to contain additives that help prevent engine and fuel system deposits from forming, allowing the emission control system to work properly. In most cases, you should not have to add anything to the fuel. However, some gasolines contain only the minimum amount of additive required to meet U.S. Environmental Protection Agency regulations. To help keep fuel injectors and intake valves clean, or if your vehicle experiences problems due to dirty injectors or valves,

look for gasoline that is advertised as TOP TIER Detergent Gasoline. Also, your dealer/retailer has additives that will help correct and prevent most deposit-related problems. Gasolines containing oxygenates, such as ethers and ethanol, and reformulated gasolines might be available in your area. We recommend that you use these gasolines, if they comply with the speciﬁcations described earlier. However, E85 (85% ethanol) and other fuels containing more than 10% ethanol must not be used in vehicles that were not designed for those fuels. Notice: Your vehicle was not designed for fuel that contains methanol. Do not use fuel containing methanol. It can corrode metal parts in the fuel system and also damage plastic and rubber parts. That damage would not be covered under your warranty. Some gasolines that are not reformulated for low emissions can contain an octane-enhancing additive called methylcyclopentadienyl manganese tricarbonyl (MMT); ask the attendant where you buy gasoline whether the fuel contains MMT. We recommend against the use of such gasolines. Fuels containing MMT can reduce the life of spark plugs and the performance of the emission control system could be affected. The malfunction indicator lamp might turn on. If this occurs, return to your dealer/retailer for service.

5-7

Fuel E85 (85% Ethanol) The 8th digit of the Vehicle Identiﬁcation Number (VIN) shows the code letter or number that identiﬁes your vehicle’s engine. The VIN is at the top left of the instrument panel. See Vehicle Identiﬁcation Number (VIN) on page 5-124. If your vehicle has the 5.3L V8 engine (VIN Code 0) or the 5.3L V8 engine (VIN Code 3), you can use either regular unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85); also see Fuel on page 5-6. In all other engines, use only the unleaded gasoline described under Gasoline Octane on page 5-6. Only vehicles that have the 5.3L V8 engine (VIN Code 0) or the 5.3L V8 engine (VIN Code 3) can use 85% ethanol fuel (E85). We encourage the use of E85 in vehicles that are designed to use it. The ethanol in E85 is a “renewable” fuel, meaning it is made from renewable sources such as corn and other crops.

Many service stations will not have an 85% ethanol fuel (E85) pump available. The U. S. Department of Energy has an alternative fuels website (www.eere.energy.gov/afdc/infrastructure/locator.html) that can help you ﬁnd E85 fuel. Those stations that do have E85 should have a label indicating ethanol content. Do not use the fuel if the ethanol content is greater than 85%. At a minimum, E85 should meet ASTM Speciﬁcation D 5798. By deﬁnition, this means that fuel labeled E85
will have an ethanol content between 70% and 85%. Filling the fuel tank with fuel mixtures that do not meet ASTM speciﬁcations can affect driveability and could cause the malfunction indicator lamp to come on. To ensure quick starts in the wintertime, the E85 fuel must be formulated properly for your climate according to ASTM speciﬁcation D 5798. If you have trouble starting on E85, it could be because the E85 fuel is not properly formulated for your climate. If this happens, switching to gasoline or adding gasoline to the fuel tank can improve starting. For good starting and heater efficiency below 32°F (0°C), the fuel mix in the fuel tank should contain no more than 70% ethanol. It is best not to alternate repeatedly between gasoline and E85.

5-8

Fuels in Foreign Countries If you plan on driving in another country outside the United States or Canada, the proper fuel might be hard to ﬁnd. Never use leaded gasoline or any other fuel not recommended in the previous text on fuel. Costly repairs caused by use of improper fuel would not be covered by your warranty. To check the fuel availability, ask an auto club, or contact a major oil company that does business in the country where you will be driving.

If you do switch fuels, it is recommended that you add as much fuel as possible — do not add less than three gallons (11 L) when refueling. You should drive the vehicle immediately after refueling for at least seven miles (11 km) to allow the vehicle to adapt to the change in ethanol concentration. E85 has less energy per gallon than gasoline, so you will need to reﬁll the fuel tank more often when using E85 than when you are using gasoline. See Filling the Tank on page 5-10. Notice: Some additives are not compatible with E85 fuel and can harm your vehicle’s fuel system. Do not add anything to E85. Damage caused by additives would not be covered by your new vehicle warranty. Notice: Your vehicle was not designed for fuel that contains methanol. Do not use fuel containing methanol. It can corrode metal parts in the fuel system and also damage plastic and rubber parts. That damage would not be covered under your warranty.

5-9

Filling the Tank If your vehicle has the DURAMAX Diesel engine, see the DURAMAX Diesel manual for more information.

{CAUTION:

Fuel vapor burns violently and a fuel ﬁre can cause bad injuries. To help avoid injuries to you and others, read and follow all the instructions on the pump island. Turn off your engine when you are refueling. Do not smoke if you are near fuel or refueling your vehicle. Do not use cellular phones. Keep sparks, ﬂames, and smoking materials away from fuel. Do not leave the fuel pump unattended when refueling your vehicle. This is against the law in some places. Do not re-enter the vehicle while pumping fuel. Keep children away from the fuel pump; never let children pump fuel.

5-10

The tethered fuel cap is located behind a hinged fuel door on the driver’s side of the vehicle. If the vehicle has E85 fuel capability, a yellow cap with the words “E85 / Gasoline” can be seen. To remove the fuel cap, turn it slowly counterclockwise.

{CAUTION:

Fuel can spray out on you if you open the fuel cap too quickly. If you spill fuel and then something ignites it, you could be badly burned. This spray can happen if your tank is nearly full, and is more likely in hot weather. Open the fuel cap slowly and wait for any hiss noise to stop. Then unscrew the cap all the way.

If your vehicle is a dual fuel tank chassis cab model, and it runs out of fuel, refuel the front fuel tank ﬁrst to ensure a quick restart. Be careful not to spill fuel. Do not top off or overﬁll the tank and wait a few seconds after you have ﬁnished pumping before removing the nozzle. Clean fuel from painted surfaces as soon as possible. See Washing Your Vehicle on page 5-118. When replacing the fuel cap, turn it clockwise until it clicks. It will require more effort to turn the fuel cap on the last turn as you tighten it. Make sure the cap is fully installed. The diagnostic system can determine if the fuel cap has been left off or improperly installed. This would allow fuel to evaporate into the atmosphere. See Malfunction Indicator Lamp on page 3-49.

The TIGHTEN GAS CAP message will be displayed on the Driver Information Center (DIC) if the fuel cap is not properly installed. See DIC Warnings and Messages on page 3-66 for more information.

{CAUTION:

If a ﬁre starts while you are refueling, do not remove the nozzle. Shut off the ﬂow of fuel by shutting off the pump or by notifying the station attendant. Leave the area immediately.

If you need a new fuel cap, be sure to get

Notice: the right type. Your dealer/retailer can get one for you. If you get the wrong type, it may not ﬁt properly. This may cause your malfunction indicator lamp to light and may damage your fuel tank and emissions system. See Malfunction Indicator Lamp on page 3-49.

5-11

Filling a Portable Fuel Container

{CAUTION:

Never ﬁll a portable fuel container while it is in your vehicle. Static electricity discharge from the container can ignite the fuel vapor. You can be badly burned and your vehicle damaged if this occurs. To help avoid injury to you and others:

(cid:127) Dispense fuel only into approved

containers.

(cid:127) Do not ﬁll a container while it is inside a

vehicle, in a vehicle’s trunk, pickup bed, or on any surface other than the ground. (cid:127) Bring the ﬁll nozzle in contact with the

inside of the ﬁll opening before operating the nozzle. Contact should be maintained until the ﬁlling is complete.

(cid:127) Do not smoke while pumping fuel. (cid:127) Do not use a cellular phone while

pumping fuel.

Checking Things Under the Hood

{CAUTION:

An electric engine cooling fan can start even when the engine is not running. To avoid injury, always keep hands, clothing, and tools away from any engine cooling fan.

{CAUTION:

Things that burn can get on hot engine parts and start a ﬁre. These include liquids like fuel, oil, coolant, brake ﬂuid, windshield washer and other ﬂuids, and plastic or rubber. You or others could be burned. Be careful not to drop or spill things that will burn onto a hot engine.

5-12

Hood Release To open the hood do the following:

1. Pull the handle with

this symbol on it. It is located inside the vehicle to the left of the brake pedal.

2. Then go to the front of the vehicle and locate the secondary hood release. This is located under the hood, near the center of the grille.

3. Push the secondary hood release to the right. 4. Lift the hood.

Before closing the hood, be sure all the ﬁller caps are on properly. Then bring the hood from full open to within 6 inches (152 mm) from the closed position, pause, then push the front center of the hood with a swift, ﬁrm motion to fully close the hood.

5-13

Engine Compartment Overview If your vehicle has the DURAMAX® Diesel engine, see the DURAMAX® Diesel manual for more information. When you open the hood on the 5.3L engine (4.3L, 4.8L and 6.0L similar), this is what you will see:

5-14

A. Engine Air Cleaner/Filter. See Engine Air

Cleaner/Filter (Gasoline Engines) on page 5-20.

B. Air Filter Restriction Indicator (If Equipped).

See Engine Air Cleaner/Filter (Gasoline Engines) on page 5-20.

C. Coolant Surge Tank and Pressure Cap. See Cooling

System on page 5-35 and Coolant Surge Tank Pressure Cap on page 5-32.

D. Positive (+) Terminal. See Jump Starting on

page 5-47.

E. Battery. See Battery on page 5-46. F. Engine Oil Fill Cap. See “When to Add Engine Oil” under Engine Oil (Gasoline Engine) on page 5-15.

G. Automatic Transmission Dipstick. See “Checking the

Fluid Level” under Automatic Transmission Fluid (6-Speed Transmission) on page 5-22 or Automatic Transmission Fluid (4-Speed Transmission) on page 5-26.

H. Remote Negative (−) Terminal (Out of View).

See Jump Starting on page 5-47.

I. Engine Oil Dipstick (Out of View). See “Checking

Engine Oil” under Engine Oil (Gasoline Engine) on page 5-15.

J. Engine Cooling Fan. See Cooling System on

page 5-35.

K. Power Steering Fluid Reservoir. See Power Steering

Fluid on page 5-41.

L. Brake Master Cylinder Reservoir. See “Brake Fluid”

under Brakes on page 5-43.

M. Underhood Fuse Block. See Underhood Fuse Block

on page 5-129.

N. Windshield Washer Fluid Reservoir. See “Adding

Washer Fluid” under Windshield Washer Fluid on page 5-42.

Engine Oil (Gasoline Engine) If your vehicle has a diesel engine, see “Engine Oil” in the DURAMAX® Diesel manual. Checking Engine Oil It is a good idea to check the engine oil every time you get fuel. In order to get an accurate reading, the oil must be warm and the vehicle must be on level ground. The engine oil dipstick handle is a yellow loop. See Engine Compartment Overview on page 5-14 for the location of the engine oil dipstick. 1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If you do not do this, the oil dipstick might not show the actual level.

2. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it again, keeping the tip down, and check the level.

5-15

When to Add Engine Oil

See Engine Compartment Overview on page 5-14
for the location of the engine oil ﬁll cap.

If the oil is below the cross-hatched area at the tip of the dipstick, add at least one quart/liter of the recommended oil. This section explains what kind of oil to use. For engine oil crankcase capacity, see Capacities and Speciﬁcations on page 5-133. Notice: Do not add too much oil. If the engine has so much oil that the oil level gets above the cross-hatched area that shows the proper operating range, the engine could be damaged.

Be sure to add enough oil to put the level somewhere in the proper operating range. Push the dipstick all the way back in when you are through.

5-16

What Kind of Engine Oil to Use

(cid:127) SAE 5W-30

As shown in the viscosity chart, SAE 5W-30 is best for your vehicle. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 20W-50.

(cid:127) Oils meeting these

requirements should have the starburst symbol on the container. This symbol indicates that the oil has been certiﬁed by the American Petroleum Institute (API).

Look for this information on the oil container, and use only those oils that are identiﬁed as meeting GM Standard GM6094M and have the starburst symbol on the front of the oil container. Notice: Use only engine oil identiﬁed as meeting GM Standard GM6094M and showing the American Petroleum Institute Certiﬁed For Gasoline Engines starburst symbol. Failure to use the recommended oil can result in engine damage not covered by your warranty.

5-17

Look for three things: (cid:127) GM6094M

Your vehicle’s engine requires oil meeting GM Standard GM6094M. Look for and use only an oil that meets GM Standard GM6094M.

When the system has calculated that oil life has been diminished, it will indicate that an oil change is necessary. A CHANGE ENGINE OIL SOON message will come on. See DIC Warnings and Messages on page 3-66. Change the oil as soon as possible within the next 600 miles (1 000 km). It is possible that, if you are driving under the best conditions, the oil life system might not indicate that an oil change is necessary for over a year. However, the engine oil and ﬁlter must be changed at least once a year and at this time the system must be reset. Your dealer/retailer has trained service people who will perform this work using genuine parts and reset the system. It is also important to check the oil regularly and keep it at the proper level. If the system is ever reset accidentally, you must change the oil at 3,000 miles (5 000 km) since your last oil change. Remember to reset the oil life system whenever the oil is changed.

If you are in an area of extreme cold, where the temperature falls below −20°F (−29°C), it is recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both provide easier cold starting and better protection for the engine at extremely low temperatures. Engine Oil Additives Do not add anything to the oil. The recommended oils with the starburst symbol that meet GM Standard GM6094M are all you need for good performance and engine protection.

Engine Oil Life System When to Change Engine Oil Your vehicle has a computer system that lets you know when to change the engine oil and ﬁlter. This is based on engine revolutions and engine temperature, and not on mileage. Based on driving conditions, the mileage at which an oil change will be indicated can vary considerably. For the oil life system to work properly, you must reset the system every time the oil is changed.

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How to Reset the Engine Oil Life System The Engine Oil Life System calculates when to change the engine oil and ﬁlter based on vehicle use. Whenever the oil is changed, reset the system so it can calculate when the next oil change is required. If a situation occurs where you change the oil prior to a CHANGE ENGINE OIL SOON message coming on, reset the system. Always reset the engine oil life to 100% after every oil change. It will not reset itself. To reset the Engine Oil Life System: 1. Display the OIL LIFE REMAINING on the DIC. If your vehicle does not have DIC buttons, the vehicle must be in PARK (P) to access this display. See DIC Operation and Displays (With DIC Buttons) on page 3-57 or DIC Operation and Displays (Without DIC Buttons) on page 3-63.

2. Press and hold the SET/RESET button on the DIC, or the trip odometer reset stem if your vehicle does not have DIC buttons, for more than ﬁve seconds. The oil life will change to 100%.

If the CHANGE ENGINE OIL SOON message comes back on when you start your vehicle, the Engine Oil Life System has not reset. Repeat the procedure.

What to Do with Used Oil Used engine oil contains certain elements that can be unhealthy for your skin and could even cause cancer. Do not let used oil stay on your skin for very long. Clean your skin and nails with soap and water, or a good hand cleaner. Wash or properly dispose of clothing or rags containing used engine oil. See the manufacturer’s warnings about the use and disposal of oil products. Used oil can be a threat to the environment. If you change your own oil, be sure to drain all the oil from the ﬁlter before disposal. Never dispose of oil by putting it in the trash, pouring it on the ground, into sewers, or into streams or bodies of water. Instead, recycle it by taking it to a place that collects used oil. If you have a problem properly disposing of used oil, ask your dealer/retailer, a service station, or a local recycling center for help.

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Engine Air Cleaner/Filter (Gasoline Engines) If your vehicle has a diesel engine, see “Pickup Models” under “Engine Air Cleaner/Filter” in the DURAMAX® Diesel Supplement for the correct inspection and replacement procedures.

See Engine Compartment Overview on page 5-14
for the location of the engine air cleaner/ﬁlter and the air ﬁlter restriction indicator, if the vehicle has one.

When to Inspect the Engine Air Cleaner/Filter If your vehicle has an air ﬁlter restriction indicator, it lets you know when the engine air cleaner/ﬁlter needs to be replaced. On vehicles with a restriction indicator, you should inspect the air ﬁlter restriction indicator at every oil change and replace the engine air cleaner/ﬁlter when the indicator tells you to. On vehicles without an air ﬁlter restriction indicator, inspect the air cleaner/ﬁlter at the Maintenance II intervals and replace it at the ﬁrst oil change after each 50,000 mile (80 000 km) interval. See Scheduled Maintenance (Gasoline Engine) on page 6-4 for more information. If you are driving in dusty/dirty conditions, inspect the ﬁlter at each engine oil change.

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How to Inspect the Engine Air Cleaner/Filter Vehicles With an Air Filter Restriction Indicator Locate the air ﬁlter restriction indicator on the engine air cleaner/ﬁlter cover. When the indicator turns black or is in the red/orange “change” zone, replace the ﬁlter and reset the indicator. See Steps 1 through 7 to replace the engine air cleaner/ﬁlter and to reset the air ﬁlter restriction indicator. Vehicles Without an Air Filter Restriction Indicator To inspect the air cleaner/ﬁlter, remove the engine air cleaner/ﬁlter from the vehicle by following Steps 1 through 7. When you have the engine air cleaner/ﬁlter removed, lightly shake it to release loose dust and dirt. If the engine air cleaner/ﬁlter remains caked with dirt, a new ﬁlter is required.

Replacing the Engine Air Cleaner/Filter and Resetting the Air Filter Restriction Indicator

1. Locate the air

cleaner/ﬁlter assembly. See Engine Compartment Overview on page 5-14.

2. Loosen the four screws on the cover of the housing

and lift up the cover.

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{CAUTION:

Operating the engine with the air cleaner/ﬁlter off can cause you or others to be burned. The air cleaner not only cleans the air; it helps to stop ﬂames if the engine backﬁres. If it is not there and the engine backﬁres, you could be burned. Do not drive with it off, and be careful working on the engine with the air cleaner/ﬁlter off.

3. Remove the engine air cleaner/ﬁlter from the housing. Care should be taken to dislodge as little dirt as possible.

4. Clean the engine air cleaner/ﬁlter sealing surfaces

and the housing.

5. Inspect or replace the engine air cleaner/ﬁlter. 6. Reinstall the cover and tighten the screws. 7. Reset the air ﬁlter restriction indicator, if the vehicle has one, by pressing the top button on the indicator.

Automatic Transmission Fluid (6-Speed Transmission) When to Check and Change Automatic Transmission Fluid It is usually not necessary to check the transmission ﬂuid level. The only reason for ﬂuid loss is a transmission leak or overheating the transmission. If you suspect a small leak, then use the following checking procedures to check the ﬂuid level.

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However, if there is a large leak, then it may be necessary to have the vehicle towed to a dealer/retailer service department and have it repaired before driving the vehicle further. Notice: Use of the incorrect automatic transmission ﬂuid may damage your vehicle, and the damages may not be covered by your warranty. Always use the automatic transmission ﬂuid listed in Recommended Fluids and Lubricants on page 6-14. Change the ﬂuid and ﬁlter at the intervals listed in the Maintenance Schedule. See Scheduled Maintenance (Gasoline Engine) on page 6-4. Be sure to use the transmission ﬂuid listed in Recommended Fluids and Lubricants on page 6-14. How to Check Automatic Transmission Fluid Notice: Too much or too little ﬂuid can damage your transmission. Too much can mean that some of the ﬂuid could come out and fall on hot engine parts or exhaust system parts, starting a ﬁre. Too little ﬂuid could cause the transmission to overheat. Be sure to get an accurate reading if you check your transmission ﬂuid.

Before checking the ﬂuid level, prepare your vehicle as follows: 1. Start the engine and park your vehicle on a level

surface. Keep the engine running.

2. Apply the parking brake and place the shift lever

in P (PARK).

3. With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, move the shift lever back to P (PARK).

4. Allow the engine to idle (500 – 800 rpm) for at least

one minute. Slowly release the brake pedal.

5. Keep the engine running and press the Trip/Fuel

button or trip odometer reset stem until TRANS TEMP (Transmission Temperature) displays on the Driver Information Center (DIC).

6. Using the TRANS TEMP reading, determine and

perform the appropriate check procedure. If the TRANS TEMP reading is not within the required temperature ranges, allow the vehicle to cool, or operate the vehicle until the appropriate transmission ﬂuid temperature is reached.

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Cold Check Procedure Use this procedure only as a reference to determine if the transmission has enough ﬂuid to be operated safely until a hot check procedure can be made. The hot check procedure is the most accurate method to check the ﬂuid level. Perform the hot check procedure at the ﬁrst opportunity. Use this cold check procedure to check ﬂuid level when the transmission temperature is between 80°F and 90°F (27°C and 32°C). 1. Locate the transmission dipstick at the rear of the

engine compartment, on the passenger side of the vehicle.

The dipstick handle has this graphic. See Engine Compartment Overview on page 5-14 for more information.

2. Flip the handle up, and then pull out the dipstick

and wipe it with a clean rag or paper towel.

3. Install the dipstick by pushing it back in all the way, wait three seconds, and then pull it back out again. 4. Check both sides of the dipstick, and read the lower

level. Repeat the check procedure to verify the reading.

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5. If the ﬂuid level is below the COLD check band, add only enough ﬂuid as necessary to bring the level into the COLD band. It does not take much ﬂuid, generally less than one pint (0.5L). Do not overﬁll.

6. Perform a hot check at the ﬁrst opportunity after

the transmission reaches a normal operating temperature between 160°F to 200°F (71°C to 93°C). 7. If the ﬂuid level is in the acceptable range, push the

dipstick back in all the way, then ﬂip the handle down to lock the dipstick in place.

Hot Check Procedure Use this procedure to check the transmission ﬂuid level when the transmission ﬂuid temperature is between 160°F and 200°F (71°C and 93°C). The hot check is the most accurate method to check the ﬂuid level. The hot check should be performed at the ﬁrst opportunity in order to verify the cold check. The ﬂuid level rises as ﬂuid temperature increases, so it is important to ensure the transmission temperature is within range. 1. Locate the transmission dipstick at the rear of the engine compartment, on the passenger side of the vehicle.

The dipstick handle has this graphic. See Engine Compartment Overview on page 5-14 for more information.

2. Flip the handle up, and then pull out the dipstick

and wipe it with a clean rag or paper towel.

3. Install the dipstick by pushing it back in all the way, wait three seconds, and then pull it back out again. 4. Check both sides of the dipstick, and read the lower

level. Repeat the check procedure to verify the reading.

5. Safe operating level is within the HOT cross hatch band on the dipstick. If the ﬂuid level is not within the HOT band, and the transmission temperature is between 160°F and 200°F (71°C and 93°C), add or drain ﬂuid as necessary to bring the level into the HOT band. If the ﬂuid level is low, add only enough ﬂuid to bring the level into the HOT band. It does not take much ﬂuid, generally less than one pint (0.5L). Do not overﬁll.

6. If the ﬂuid level is in the acceptable range, push the

dipstick back in all the way, then ﬂip the handle down to lock the dipstick in place.

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Consistency of Readings Always check the ﬂuid level at least twice using the procedures described. Consistency (repeatable readings) is important to maintaining proper ﬂuid level. If ﬂuid is added, it may take 15 minutes or longer to obtain an accurate reading because of residual ﬂuid draining down the dipstick tube. If inconsistent readings persist, check the transmission breather to be sure it is clean and not clogged. If readings are still inconsistent, contact your dealer/retailer.

Automatic Transmission Fluid (4-Speed Transmission) When to Check and Change Automatic Transmission Fluid A good time to check your automatic transmission ﬂuid level is when the engine oil is changed. Change the ﬂuid and ﬁlter at the intervals listed in Additional Required Services on page 6-6, and be sure to use the transmission ﬂuid listed in Recommended Fluids and Lubricants on page 6-14.

How to Check Automatic Transmission Fluid Because this operation can be a little difficult, you may choose to have this done at the dealer/retailer service department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading on the dipstick. Notice: Too much or too little ﬂuid can damage your transmission. Too much can mean that some of the ﬂuid could come out and fall on hot engine parts or exhaust system parts, starting a ﬁre. Too little ﬂuid could cause the transmission to overheat. Be sure to get an accurate reading if you check your transmission ﬂuid. Wait at least 30 minutes before checking the transmission ﬂuid level if you have been driving: (cid:127) When outside temperatures are above 90°F (32°C). (cid:127) At high speed for quite a while. (cid:127) In heavy traffic — especially in hot weather. (cid:127) While pulling a trailer. To get the right reading, the ﬂuid should be at normal operating temperature, which is 180°F to 200°F (82°C to 93°C).

5-26

Then, without shutting off the engine, follow these steps:

The transmission dipstick handle with this graphic is located at the rear of the engine compartment, on the passenger’s side of the vehicle.

See Engine Compartment Overview on page 5-14 for more information on location. 1. Flip the handle up and then pull out the dipstick

and wipe it with a clean rag or paper towel.

2. Push it back in all the way, wait three seconds and

then pull it back out again.

Get the vehicle warmed up by driving about 15 miles (24 km) when outside temperatures are above 50°F (10°C). If it is colder than 50°F (10°C), drive the vehicle in 3 (Third) until the engine temperature gage moves and then remains steady for 10 minutes. A cold ﬂuid check can be made after the vehicle has been sitting for eight hours or more with the engine off, but this is used only as a reference. Let the engine run at idle for ﬁve minutes if outside temperatures are 50°F (10°C) or more. If it is colder than 50°F (10°C), you may have to idle the engine longer. Should the ﬂuid level be low during this cold check, you must check the ﬂuid hot before adding ﬂuid. Checking the ﬂuid hot will give you a more accurate reading of the ﬂuid level. Checking the Fluid Level Prepare your vehicle as follows: 1. Park your vehicle on a level place. Keep the engine

running.

2. With the parking brake applied, place the shift lever

in P (Park).

3. With your foot on the brake pedal, move the shift lever through each gear range, pausing for about three seconds in each range. Then, position the shift lever in P (Park).

4. Let the engine run at idle for three minutes or more.

5-27

How to Add Automatic Transmission Fluid Refer to the Maintenance Schedule to determine what kind of transmission ﬂuid to use. See Recommended Fluids and Lubricants on page 6-14. Using a funnel, add ﬂuid down the transmission dipstick tube only after checking the transmission ﬂuid while it is hot. A cold check is used only as a reference. If the ﬂuid level is low, add only enough of the proper ﬂuid to bring the level up to the HOT area for a hot check. It does not take much ﬂuid, generally less than one pint (0.5 L). Do not overﬁll. Notice: Use of the incorrect automatic transmission ﬂuid may damage your vehicle, and the damages may not be covered by your warranty. Always use the automatic transmission ﬂuid listed in Recommended Fluids and Lubricants on page 6-14. (cid:127) After adding ﬂuid, recheck the ﬂuid level as described under “How to Check Automatic Transmission Fluid,” earlier in this section.

(cid:127) When the correct ﬂuid level is obtained, push the

dipstick back in all the way; then ﬂip the handle down to lock the dipstick in place.

3. Check both sides of the dipstick, and read the lower

level. The ﬂuid level must be in the COLD area, below the cross-hatched area, for a cold check or in the HOT or cross-hatched area for a hot check. Be sure to keep the dipstick pointed down to get an accurate reading.

4. If the ﬂuid level is in the acceptable range, push the

dipstick back in all the way; then ﬂip the handle down to lock the dipstick in place.

Consistency of Readings Always check the ﬂuid level at least twice using the procedure described previously. Consistency (repeatable readings) is important to maintaining proper ﬂuid level. If readings are still inconsistent, contact your dealer/retailer.

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Engine Coolant If your vehicle has the DURAMAX® Diesel engine, see the DURAMAX® Diesel manual for more information. The cooling system in your vehicle is ﬁlled with DEX-COOL® engine coolant. This coolant is designed to remain in your vehicle for ﬁve years or 150,000 miles (240 000 km), whichever occurs ﬁrst, if you add only DEX-COOL® extended life coolant. The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see Engine Overheating on page 5-32.

A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will: (cid:127) Give freezing protection down to −34°F (−37°C). (cid:127) Give boiling protection up to 265°F (129°C). (cid:127) Protect against rust and corrosion. (cid:127) Help keep the proper engine temperature. (cid:127) Let the warning lights and gages work as they

should.

Notice: Using coolant other than DEX-COOL® may cause premature engine, heater core, or radiator corrosion. In addition, the engine coolant may require changing sooner, at the ﬁrst maintenance service after each 30,000 miles (50 000 km) or 24 months, whichever occurs ﬁrst. Any repairs would not be covered by your warranty. Always use DEX-COOL® (silicate-free) coolant in your vehicle.

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If you use an improper coolant mixture,

Notice: your engine could overheat and be badly damaged. The repair cost would not be covered by your warranty. Too much water in the mixture can freeze and crack the engine, radiator, heater core, and other parts. If you have to add coolant more than four times a year, have your dealer/retailer check your cooling system. Notice: in your vehicle’s cooling system, you could damage your vehicle. Use only the proper mixture of the engine coolant listed in this manual for the cooling system. See Recommended Fluids and Lubricants on page 6-14 for more information.

If you use extra inhibitors and/or additives

What to Use Use a mixture of one-half clean, drinkable water and one-half DEX-COOL® coolant which will not damage aluminum parts. If you use this coolant mixture, you do not need to add anything else.

{CAUTION:

Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. Your vehicle’s coolant warning system is set for the proper coolant mixture. With plain water or the wrong mixture, your engine could get too hot but you would not get the overheat warning. Your engine could catch ﬁre and you or others could be burned. Use a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant.

5-30

Checking Coolant The coolant surge tank is located in the engine compartment on the passenger’s side of the vehicle. See Engine Compartment Overview on page 5-14
for more information on location.

Adding Coolant If you need more coolant, add the proper DEX-COOL® coolant mixture at the surge tank, but only when the engine is cool. See Cooling System on page 5-35
for more information.

{CAUTION:

{CAUTION:

You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine.

When replacing the pressure cap, make sure it is hand-tight and fully seated.

Turning the surge tank pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure cap — even a little — when the engine and radiator are hot.

The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the FULL COLD mark on the coolant surge tank. If your vehicle has a low coolant sensor and the LOW COOLANT LEVEL message comes on and stays on, it means you are low on engine coolant. See “LOW COOLANT LEVEL” under DIC Warnings and Messages on page 3-66.

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Coolant Surge Tank Pressure Cap If the pressure cap is not tightly installed, Notice: coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured. The coolant surge tank pressure cap must be fully installed on the coolant surge tank. See Engine Compartment Overview on page 5-14 for more information on location.

Engine Overheating If your vehicle has the DURAMAX® Diesel engine, see the DURAMAX® Diesel manual for more information. You will ﬁnd a coolant temperature gage on your vehicle’s instrument panel. See Engine Coolant Temperature Gage on page 3-48. In addition, you will ﬁnd ENGINE OVERHEATED STOP ENGINE, ENGINE OVERHEATED IDLE ENGINE, and ENGINE POWER IS REDUCED messages in the Driver Information Center (DIC) on the instrument panel. See DIC Warnings and Messages on page 3-66.

If Steam Is Coming From Your Engine

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2008 Chevrolet Silverado Owners Manual