2008 GMC Sierra Owners Manual

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you put things in the bed of your truck, you should make sure they are properly secured.

{CAUTION:

Do not load your vehicle any heavier than the Gross Vehicle Weight Rating (GVWR), or either the maximum front or rear Gross Axle Weight Rating (GAWR). If you do, parts on your vehicle can break, and it can change the way your vehicle handles. These could cause you to lose control and crash. Also, overloading can shorten the life of your vehicle.

Notice: Overloading your vehicle may cause damage. Repairs would not be covered by your warranty. Do not overload your vehicle. Using heavier suspension components to get added durability might not change the vehicle’s weight ratings. Ask your dealer to help you load your vehicle the right way. If things are put inside your vehicle — like suitcases, tools, packages, or anything else — they go as fast as the vehicle goes. If you have to stop or turn quickly, or if there is a crash, they will keep going.

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{CAUTION:

Things you put inside your vehicle can strike and injure people in a sudden stop or turn, or in a crash.

(cid:129) Put things in the cargo area of your

vehicle. Try to spread the weight evenly.

(cid:129) Never stack heavier things, like

suitcases, inside the vehicle so that some of them are above the tops of the seats.

(cid:129) Do not leave an unsecured child

restraint in your vehicle.

(cid:129) When you carry something inside the vehicle, secure it whenever you can.

(cid:129) Do not leave a seat folded down

unless you need to.

There is also important loading information for off-road driving in this manual. See “Loading Your Vehicle for Off-Road Driving“ under Off-Road Driving on page 4-12.

Two-Tiered Loading By positioning four 2” x 6” wooden planks across the width of the pickup box, you can create an upper load platform. The planks must be inserted in the pickup box depressions. The length of the planks must allow for at least a 3/4 inch (2 cm) bearing surface on each end of the plank. When using this upper load platform, be sure the load is securely tied down to prevent it from shifting. The load’s center of gravity should be positioned in a zone over the rear axle. The zone is located in the area between the front of each wheel well and the rear of each wheel well. The center of gravity height must not extend above the top of the pickup box ﬂareboard. Any load that extends beyond the vehicle’s taillamp area must be properly marked according to local laws and regulations. Remember not to exceed the Gross Axle Weight Rating (GAWR) of the front or rear axle.

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Add-On Equipment When you carry removable items, you may need to put a limit on how many people you carry inside your vehicle. Be sure to weigh your vehicle before you buy and install the new equipment. Notice: Overloading your vehicle may cause damage. Repairs would not be covered by your warranty. Do not overload your vehicle. Remember not to exceed the Gross Axle Weight Rating (GAWR) of the front or rear axle.

*Equipment Ladder Rack and Cargo

Cross Toolbox

and Cargo Side Boxes and Cargo

Maximum Weight

750 lbs (340 kg)

400 lbs (181 kg)

250 lbs per side (113 kg per side)

*The combined weight for all rail-mounted equipment should not exceed 1,000 lbs (454 kg). A reinforcement kit for rail-mounted add-on equipment is recommended. See your GM dealer.

Truck-Camper Loading Information Your vehicle was neither designed nor intended to carry a slide-in type camper. Notice: Adding a slide-in camper or similar equipment to your vehicle can damage it, and the repairs would not be covered by your warranty. Do not install a slide-in camper or similar equipment on your vehicle.

Pickup Conversion to Chassis Cab We are aware that some vehicle owners might consider having the pickup box removed and a commercial or recreational body installed. Owners should be aware that, as manufactured, there are differences between a chassis cab and a pickup with the box removed which could affect vehicle safety. The components necessary to adapt a pickup to permit its safe use with a specialized body should be installed by the body builder.

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Towing

Towing Your Vehicle Consult your dealer/retailer or a professional towing service if you need to have your disabled vehicle towed. See Roadside Assistance Program on page 7-6. If you want to tow your vehicle behind another vehicle for recreational purposes (such as behind a motorhome), see “Recreational Vehicle Towing” following.

Recreational Vehicle Towing Recreational vehicle towing means towing your vehicle behind another vehicle — such as behind a motorhome. The two most common types of recreational vehicle towing are known as “dinghy towing” (towing your vehicle with all four wheels on the ground) and “dolly towing” (towing your vehicle with two wheels on the ground and two wheels up on a device known as a “dolly”). Your vehicle was not designed to be towed with any of its wheels on the ground. If your vehicle must be towed, see Towing Your Vehicle on page 4-41.

Notice: Towing an all-wheel-drive vehicle with all four wheels on the ground, or even with only two of its wheels on the ground, will damage drivetrain components. Do not tow an all-wheel-drive vehicle if any of its wheels will be on the ground.

Towing a Trailer Do not tow a trailer during break-in. See New Vehicle Break-In on page 2-22 for more information.

{CAUTION:

If you do not use the correct equipment and drive properly, you can lose control when you pull a trailer. For example, if the trailer is too heavy, the brakes may not work well — or even at all. You and your passengers could be seriously injured. You may also damage your vehicle; the resulting repairs would not be covered by your warranty. Pull a trailer only if you have followed all the steps in this section. Ask your dealer/retailer for advice and information about towing a trailer with your vehicle.

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Notice: Pulling a trailer improperly can damage your vehicle and result in costly repairs that would not be covered by your warranty. Always follow the instructions in this section and check with your dealer/retailer for more information about towing a trailer with your vehicle. To identify the trailering capacity of your vehicle, you should read the information in “Weight of the Trailer” that appears later in this section. Trailering is different than just driving your vehicle by itself. Trailering means changes in acceleration, braking, handling, durability and fuel economy. Successful, safe trailering takes correct equipment, and it has to be used properly. That’s the reason for this part. In it are many time-tested, important trailering tips and safety rules. Many of these are important for your safety and that of your passengers. So please read this section carefully before you pull a trailer.

If You Do Decide To Pull A Trailer If you do, here are some important points:

There are many different laws, including speed limit restrictions, having to do with trailering. Make sure your rig will be legal, not only where you live but also where you’ll be driving. A good source for this information can be state or provincial police.

(cid:129) Consider using a sway control. See “Hitches” later

in this section.

(cid:129) Don’t tow a trailer at all during the ﬁrst 500 miles (800 km) your new vehicle is driven. Your engine, axle or other parts could be damaged. Then, during the ﬁrst 500 miles (800 km) that you tow a trailer, don’t drive over 50 mph (80 km/h) and don’t make starts at full throttle. This helps your engine and other parts of your vehicle wear in at the heavier loads.

(cid:129) You can tow in DRIVE (D). You may want to shift

the transmission to Manual Mode and select a lower gear if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). See “Tow/Haul Mode“ later in this section.

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(cid:129) (cid:129) Three important considerations have to do with weight:

the weight of the trailer the weight of the trailer tongue and the weight on your vehicle’s tires

Tow/Haul Mode Tow/Haul is a feature that assists when pulling a heavy trailer or a large or heavy load. The purpose of the Tow/Haul mode is to: (cid:129) Reduce the frequency and improve the predictability of transmission shifts when pulling a heavy trailer or a large or heavy load.

(cid:129) Provide the same solid shift feel when pulling a heavy trailer or a large or heavy load as when the vehicle is unloaded. Improve control of vehicle speed while requiring less throttle pedal activity when pulling a heavy trailer or a large or heavy load. Increase the charging system voltage to assist in recharging a battery installed in a trailer.

Press this button at the end of the shift lever to enable/disable the tow/haul mode.

A light on the instrument panel will illuminate to indicate that tow/haul mode has been selected.

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(cid:129) (cid:129) (cid:129) (cid:129) (cid:129) Tow/Haul may be turned off by pressing the switch again, at which time the indicator light on the instrument panel cluster will turn off. The vehicle will automatically turn off Tow/Haul every time it is started. Tow/Haul is designed to be most effective when the vehicle and trailer combined weight is at least 75 percent of the vehicle’s Gross Combined Weight Rating (GCWR). See Weight of the Trailer later in this section. Tow/haul is most useful under the following driving conditions: (cid:129) When pulling a heavy trailer or a large or heavy

load through rolling terrain.

(cid:129) When pulling a heavy trailer or a large or heavy

load in stop and go traffic.

(cid:129) When pulling a heavy trailer or a large or heavy

load in busy parking lots where improved low speed control of the vehicle is desired.

Operating the vehicle in Tow/Haul when lightly loaded or with no trailer at all will not cause damage. However, there is no beneﬁt to the selection of Tow/Haul when the vehicle is unloaded.

Such a selection when unloaded may result in unpleasant engine and transmission driving characteristics and reduced fuel economy. Tow/Haul is recommended only when pulling a heavy trailer or a large or heavy load. Weight of the Trailer How heavy can a trailer safely be? It depends on how you plan to use your rig. For example, speed, elevation, road grades, outside temperature and how much your vehicle is used to pull a trailer are all important. It can also depend on any special equipment that you have on your vehicle, and the amount of tongue weight the vehicle can carry. See “Weight of the Trailer Tongue” later in this section for more information. Maximum trailer weight is calculated assuming only the driver is in the tow vehicle and it has all the required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle must be subtracted from the maximum trailer weight.

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Use the following chart to determine how much your vehicle can weigh, based upon your vehicle model and options.

C-1500*

Axle Ratio

Maximum Trailer Weight

**GCWR

6.2L V8
*Fifth-wheel or gooseneck trailering is neither designed nor intended for this vehicle. **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.

14,000 lbs (6 350 kg)

8,600 lbs (3 900 kg)

3.42

K-1500*

Axle Ratio

Maximum Trailer Weight

**GCWR

6.2L V8
*Fifth-wheel or gooseneck trailering is neither designed nor intended for this vehicle. **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.

14,000 lbs (6 350 kg)

8,400 lbs (3 810 kg)

3.42

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. Weight of 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 4-34 for more information about your vehicle’s maximum load capacity.

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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 trailer tongue weight (A) should be 10 percent to 15 percent of the total loaded trailer weight (B), up to a maximum or 600 lbs (272 kg) 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) with a weight distributing hitch. 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.

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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). 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:

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.

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).

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Weight Distributing Hitches and Weight Carrying Hitches

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. 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.

(A) Body to Ground Distance (B) Front of Vehicle

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.

4-48

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/retailer about sway controls. Safety Chains You should always attach safety 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. You may attach the safety chains to the attaching point on the hitch platform. 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:

The trailer parts can withstand 3,000 psi (20 650 kPa) of pressure. 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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(cid:129) (cid:129) 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. 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.

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 2-35. To maximize your safety when towing a trailer:

(cid:129) Have your exhaust system inspected for leaks, and make necessary repairs before starting on your trip.

(cid:129) Keep the rear-most windows closed.

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 Dual Automatic Climate Control System on page 3-26.

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(cid:129) 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. 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.

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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 THIRD (3) or, if necessary, a 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” earlier 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 automatic transmission in PARK (P) for a few minutes before turning the engine off. If you do get the overheat warning, see Engine Overheating on page 5-26.

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. Release the regular brakes.

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

while you:

start your engine, shift into a gear, and 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 the Maintenance Schedule for more on this. Things that are especially important in trailer operation are automatic transmission ﬂuid (don’t overﬁll), engine oil, axle lubricant, belts, 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.

Trailer Wiring Harness

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:129) Yellow: Left Stop/Turn Signal (cid:129) Dark Green: Right Stop/Turn Signal (cid:129) Brown: Taillamps (cid:129) White: Ground

Light Green: Back-up Lamps

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(cid:129) (cid:129) (cid:129) (cid:129) The harness contains the following wires: (cid:129) Dark Blue: Brake Signal to Trailer Connector (cid:129) Red/Black: Battery

Light Blue/White: Brake Switch

(cid:129) White: Ground It should be installed by your dealer/retailer or a qualiﬁed service center.

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 4-41.

(cid:129) Red: Battery Feed* (cid:129) 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/retailer or a qualiﬁed service center. 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/retailer 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. 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.

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(cid:129) Section 5

Service and Appearance Care

Service ............................................................5-3
Accessories and Modiﬁcations ..........................5-3
California Proposition 65 Warning .....................5-4
California Perchlorate Materials Requirements .....5-4
Doing Your Own Service Work .........................5-4
Adding Equipment to the Outside

of Your Vehicle ...........................................5-5
Fuel ................................................................5-5
Gasoline Octane ............................................5-5
Gasoline Speciﬁcations ....................................5-5
California Fuel ...............................................5-6
Additives .......................................................5-6
Fuels in Foreign Countries ...............................5-7
Filling the Tank ..............................................5-8
Filling a Portable Fuel Container .....................5-10
Checking Things Under the Hood ....................5-10
Hood Release ..............................................5-11
Engine Compartment Overview .......................5-12
Engine Oil ...................................................5-13
Engine Oil Life System ..................................5-16
Engine Air Cleaner/Filter ................................5-17
Automatic Transmission Fluid .........................5-20
Engine Coolant .............................................5-23
Coolant Surge Tank Pressure Cap ..................5-26
Engine Overheating .......................................5-26
Overheated Engine Protection Operating Mode ...5-28
Cooling System ............................................5-29

Engine Fan Noise .........................................5-33
Power Steering Fluid .....................................5-34
Windshield Washer Fluid ................................5-35
Brakes ........................................................5-36
Battery ........................................................5-39
Jump Starting ...............................................5-40
All-Wheel Drive ..............................................5-45
Rear Axle .......................................................5-46
Front Axle ......................................................5-47
Headlamp Aiming ...........................................5-49
Bulb Replacement ..........................................5-52
Halogen Bulbs ..............................................5-52
Headlamps ..................................................5-52
Front Turn Signal, Sidemarker and Daytime

Running Lamps .........................................5-53

Center High-Mounted Stoplamp (CHMSL)

and Cargo Lamp .......................................5-54

Taillamps, Turn Signal, Stoplamps and

Back-up Lamps .........................................5-55
License Plate Lamp ......................................5-56
Replacement Bulbs .......................................5-57
Windshield Wiper Blade Replacement ..............5-57
Tires ..............................................................5-58
Tire Sidewall Labeling ...................................5-59
Tire Terminology and Deﬁnitions .....................5-62
Inﬂation - Tire Pressure .................................5-65

5-1

Section 5

Service and Appearance Care

Tire Pressure Monitor System .........................5-66
Tire Pressure Monitor Operation .....................5-68
Tire Inspection and Rotation ...........................5-72
When It Is Time for New Tires .......................5-73
Buying New Tires .........................................5-74
Different Size Tires and Wheels ......................5-76
Uniform Tire Quality Grading ..........................5-76
Wheel Alignment and Tire Balance ..................5-78
Wheel Replacement ......................................5-78
Tire Chains ..................................................5-79
If a Tire Goes Flat ........................................5-80
Changing a Flat Tire .....................................5-81
Removing the Spare Tire and Tools ................5-82
Removing the Flat Tire and Installing

the Spare Tire ..........................................5-85
Secondary Latch System ...............................5-91
Storing a Flat or Spare Tire and Tools ............5-94
Spare Tire ...................................................5-98
Appearance Care ............................................5-98
Interior Cleaning ...........................................5-98
Fabric/Carpet ..............................................5-100
Leather ......................................................5-100
Instrument Panel, Vinyl, and Other

Plastic Surfaces .......................................5-101
Wood Panels ..............................................5-101
Care of Safety Belts ....................................5-101

Weatherstrips .............................................5-102
Washing Your Vehicle ..................................5-102
Cleaning Exterior Lamps/Lenses ....................5-102
Finish Care ................................................5-102
Windshield and Wiper Blades .......................5-103
Aluminum or Chrome-Plated

Wheels and Trim .....................................5-104
Tires .........................................................5-105
Sheet Metal Damage ...................................5-105
Finish Damage ...........................................5-105
Underbody Maintenance ...............................5-105
Chemical Paint Spotting ...............................5-105
Vehicle Care/Appearance Materials ................5-106
Vehicle Identiﬁcation .....................................5-107
Vehicle Identiﬁcation Number (VIN) ................5-107
Service Parts Identiﬁcation Label ...................5-107
Electrical System ..........................................5-108
Add-On Electrical Equipment .........................5-108
Windshield Wiper Fuses ...............................5-108
Power Windows and Other

Power Options ........................................5-108
Fuses and Circuit Breakers ..........................5-108
Instrument Panel Fuse Block ........................5-109
Center Instrument Panel Fuse Block ..............5-111
Underhood Fuse Block ................................5-112
Capacities and Speciﬁcations ........................5-116

5-2

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:

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 1-68.

5-3

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.

5-4

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:129) Be sure you have sufficient knowledge,

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

(cid:129) 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 1-68. 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 6-16.

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. Fuel 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.

Gasoline Octane Use premium unleaded gasoline with a posted octane rating of 91 or higher. You can also use regular unleaded gasoline rated at 87 octane or higher, but your vehicle’s acceleration could be slightly reduced, and you might notice a slight audible knocking noise, commonly referred to as spark knock. If the octane is less than 87, you might notice a heavy knocking noise when you drive. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. Otherwise, you could damage the engine. 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 5-6 for additional information.

5-5

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 3-44. 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 your 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.

5-6

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.

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.

5-7

Filling the Tank

{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.

5-8

The tethered fuel cap is located behind a hinged fuel door on the driver’s side of the vehicle. To remove the fuel cap, turn it slowly counterclockwise.

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 3-59 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.

Notice: If you need a new fuel cap, be sure to get 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 3-44.

{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 5-102. 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 3-44.

5-9

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:

Checking Things Under the Hood

{CAUTION:

An electric fan under the hood can start up and injure you even when the engine is not running. Keep hands, clothing, and tools away from any underhood electric fan.

(cid:129) Dispense fuel only into approved

containers.

(cid:129) 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:129) 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:129) Do not smoke while pumping fuel. (cid:129) Do not use a cellular phone while

pumping fuel.

{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.

5-10

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.

5-11

Engine Compartment Overview When you open the hood on the 6.2L engine this is what you will see:

5-12

A. Engine Air Cleaner/Filter. See Engine Air

Cleaner/Filter on page 5-17.

B. Air Filter Restriction Indicator (If Equipped). See Engine Air Cleaner/Filter on page 5-17.

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

under Brakes on page 5-36.

M. Underhood Fuse Block. See Underhood Fuse Block

on page 5-112.

C. Coolant Surge Tank and Pressure Cap. See Cooling

System on page 5-29 and Coolant Surge Tank Pressure Cap on page 5-26.

N. Windshield Washer Fluid Reservoir. See “Adding

Washer Fluid” under Windshield Washer Fluid on page 5-35.

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

on page 5-40.

E. Battery. See Battery on page 5-39. F. Engine Oil Fill Cap. See “When to Add Engine Oil”

under Engine Oil on page 5-13.

G. Automatic Transmission Dipstick (Out of View). See “Checking the Fluid Level” under Automatic Transmission Fluid on page 5-20.

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

See Jump Starting on page 5-40.

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

Engine Oil” under Engine Oil on page 5-13.

J. Engine Cooling Fan (Out of View). See Cooling

System on page 5-29.

K. Power Steering Fluid Reservoir (Out of View).

See Power Steering Fluid on page 5-34.

Engine Oil 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 5-12 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.

5-13

When to Add Engine Oil

See Engine Compartment Overview on page 5-12
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 5-116. 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.

5-14

What Kind of Engine Oil to Use

Look for three things: (cid:129) GM6094M

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

(cid:129) 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:129) 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. 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.

5-15

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. 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 3-59. 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. 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 being turned 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. 2. Press and hold the SET/RESET button on the DIC for more than ﬁve seconds. The oil life will change to 100%.

5-16

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.

Engine Air Cleaner/Filter

See Engine Compartment Overview on page 5-12
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 on page 6-4 for more information. If you are driving in dusty/dirty conditions, inspect the ﬁlter at each engine oil change.

5-17

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 the steps following 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 6. 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 5-12.

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

and lift up the cover.

5-18

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.

{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.

5-19

Automatic Transmission Fluid 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. 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 6-12. Change the ﬂuid and ﬁlter at the intervals listed in the Maintenance Schedule. See Scheduled Maintenance on page 6-4. Be sure to use the transmission ﬂuid listed in Recommended Fluids and Lubricants on page 6-12. 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.

5-20

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 PARK (P).

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 PARK (P).

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.

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 5-12 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. 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.

5-21

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 5-12 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.

5-22

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.

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.

Engine Coolant 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 5-26.

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

5-23

(cid:129) If you use an improper coolant mixture, your

Notice: 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: If you use extra inhibitors and/or additives 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 6-12 for more information.

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.

5-24

Checking Coolant

The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the FULL COLD mark. Adding Coolant If more coolant is needed, add the proper DEX-COOL® coolant mixture at the surge tank, but only when the engine is cool.

{CAUTION:

The coolant surge tank is located in the engine compartment on the passenger’s side of the vehicle. See Engine Compartment Overview on page 5-12
for more information on location.

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.

{CAUTION:

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.

5-25

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 5-12 for more information on location.

Engine Overheating There is a coolant temperature gage on your vehicle’s instrument panel. See Engine Coolant Temperature Gage on page 3-43. In addition, ENGINE OVERHEATED STOP ENGINE, ENGINE OVERHEATED IDLE ENGINE, and a ENGINE POWER IS REDUCED message comes on in the Driver Information Center (DIC) on the instrument panel. See DIC Warnings and Messages on page 3-59.

If Steam Is Coming From Your Engine

{CAUTION:

Steam from an overheated engine can burn you badly, even if you just open the hood. Stay away from the engine if you see or hear steam coming from it. Turn it off and get everyone away from the vehicle until it cools down. Wait until there is no sign of steam or coolant before you open the hood. If you keep driving when the vehicles engine is overheated, the liquids in it can catch ﬁre. You or others could be badly burned. Stop your engine if it overheats, and get out of the vehicle until the engine is cool. See Overheated Engine Protection Operating Mode on page 5-28 for information on driving to a safe place in an emergency.

5-26

If your engine catches ﬁre because you keep

Notice: driving with no coolant, your vehicle can be badly damaged. The costly repairs would not be covered by your warranty. See Overheated Engine Protection Operating Mode on page 5-28 for information on driving to a safe place in an emergency.

If No Steam Is Coming From Your Engine The ENGINE OVERHEATED STOP ENGINE or the ENGINE OVERHEATED IDLE ENGINE message, along with a low coolant condition, can indicate a serious problem. If you get an engine overheat warning, but see or hear no steam, the problem may not be too serious. Sometimes the engine can get a little too hot when you: (cid:129) Climb a long hill on a hot day. (cid:129) Stop after high-speed driving. Idle for long periods in traffic. Tow a trailer. See Towing a Trailer on page 4-41.

If you get the ENGINE OVERHEATED STOP ENGINE or the ENGINE OVERHEATED IDLE ENGINE message with no sign of steam, try this for a minute or so: 1. If the vehicle has an air conditioner and it is on,

turn it off.

2. Turn on the heater to the highest temperature and

at the highest fan speed and open the windows as necessary.

3. In heavy traffic, let the engine idle in NEUTRAL (N) while stopped. If it is safe to do so, pull off the road, shift to PARK (P) or NEUTRAL (N) and let the engine idle.

If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about 10 minutes. If the warning does not come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle immediately.

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(cid:129) (cid:129) If there is still no sign of steam and your vehicle has an engine-driven cooling fan, push down the accelerator until the engine speed is about twice as fast as normal idle speed for at least ﬁve minutes while parked. If there is still no sign of steam and your vehicle has an electric cooling fan, idle the engine for ﬁve minutes while parked. If you still have the warning, turn off the engine and get everyone out of the vehicle until it cools down. Also, see “Overheated Engine Protection Operating Mode” later in this section. You might decide not to lift the hood but to get service help right away.

Overheated Engine Protection Operating Mode If an overheated engine condition exists and the ENGINE POWER IS REDUCED message is displayed, an overheat protection mode which alternates ﬁring groups of cylinders helps prevent engine damage. In this mode, you will notice a loss in power and engine performance. This operating mode allows your vehicle to be driven to a safe place in an emergency. Driving extended miles (km) and/or towing a trailer in the overheat protection mode should be avoided. Notice: After driving in the overheated engine protection operating mode, to avoid engine damage, allow the engine to cool before attempting any repair. The engine oil will be severely degraded. Repair the cause of coolant loss, change the oil and reset the oil life system. See Engine Oil on page 5-13.

5-28

Cooling System When you decide it is safe to lift the hood, this is what you will see:

{CAUTION:

An electric engine cooling fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing, and tools away from any underhood electric fan.

If the coolant inside the coolant surge tank is boiling, do not do anything else until it cools down. The vehicle should be parked on a level surface. Check the coolant level after the system cools down. Some amount of coolant can be lost due to overheating.

A. Coolant Surge Tank B. Coolant Surge Tank Pressure Cap C. Engine Cooling Fan

5-29

{CAUTION:

Heater and radiator hoses, and other engine parts, can be very hot. Do not touch them. If you do, you can be burned. Do not run the engine if there is a leak. If you run the engine, it could lose all coolant. That could cause an engine ﬁre, and you could be burned. Get any leak ﬁxed before you drive the vehicle.

Notice: Engine damage from running your engine without coolant is not covered by your warranty. See Overheated Engine Protection Operating Mode on page 5-28 for information on driving to a safe place in an emergency. Notice: Using coolant other than DEX-COOL® may cause premature engine, heater core, or radiator corrosion. In addition, the engine coolant could require changing sooner, at 30,000 miles (50 000 km) or 24 months, whichever occurs ﬁrst. Any repairs would not be covered by the warranty. Always use DEX-COOL® (silicate-free) coolant in the vehicle.

The coolant level should be at or above the FULL COLD mark. If it is not, you could have a leak at the pressure cap or in the radiator hoses, heater hoses, radiator, water pump, or somewhere else in the cooling system.

5-30

How to Add Coolant to the Coolant Surge Tank If you have not found a problem yet, check to see if coolant is visible in the surge tank. If coolant is visible but the coolant level is not at or above the FULL COLD mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant at the coolant surge tank, but be sure the cooling system, including the coolant surge tank pressure cap, is cool before you do it. See Engine Coolant on page 5-23 for more information.

If no coolant is visible in the surge tank, add coolant as follows:

{CAUTION:

Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the radiator pressure cap — even a little — they can come out at high speed. Never turn the cap when the cooling system, including the radiator pressure cap, is hot. Wait for the cooling system and radiator pressure cap to cool if you ever have to turn the pressure cap.

5-31

{CAUTION:

{CAUTION:

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

In cold weather, water can freeze and crack

Notice: the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mixture.

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.

1. Remove the coolant surge tank pressure cap when the cooling system, including the coolant surge tank pressure cap and upper radiator hose, is no longer hot.

Remove the coolant surge tank pressure cap by slowly turning the pressure cap counterclockwise about one full turn. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.

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2. Then keep turning the pressure cap slowly,

and remove it.

3. Fill the coolant surge tank with the proper mixture,

to the FULL COLD mark.

4. With the coolant surge tank pressure cap off, start the engine and let it run until the engine coolant temperature gage indicates approximately 195°F (90°C).

By this time, the coolant level inside the coolant surge tank could be lower. If the level is lower, add more of the proper mixture to the coolant surge tank until the level reaches the FULL COLD mark.

5. Then replace the pressure cap. Be sure the pressure cap is hand-tight and fully seated.

6. Verify coolant level after the engine is shut off

and the coolant is cold. If necessary, repeat coolant ﬁll procedure Steps 1 through 6.

Engine Fan Noise Your vehicle has electric cooling fans. You might hear the fans spinning at low speed during most everyday driving. The fans can turn off if no cooling is required. Under heavy vehicle loading, trailer towing, and/or high outside temperatures, or if you are operating the air conditioning system, the fans can change to high speed and you might hear an increase in fan noise. This is normal and indicates that the cooling system is functioning properly. The fans change to low speed when additional cooling is no longer required.

5-33

Power Steering Fluid

See Engine Compartment Overview on page 5-12
for reservoir location.

When to Check Power Steering Fluid It is not necessary to regularly check power steering ﬂuid unless you suspect there is a leak in the system or you hear an unusual noise. A ﬂuid loss in this system could indicate a problem. Have the system inspected and repaired.

5-34

How to Check Power Steering Fluid To check the power steering ﬂuid, do the following: 1. Turn the key off and let the engine compartment

cool down.

2. Wipe the cap and the top of the reservoir clean. 3. Unscrew the cap and wipe the dipstick with a

clean rag.

4. Replace the cap and completely tighten it. 5. Remove the cap again and look at the ﬂuid level

on the dipstick.

The level should be at the FULL COLD mark. If necessary, add only enough ﬂuid to bring the level up to the mark. What to Use To determine what kind of ﬂuid to use, see Recommended Fluids and Lubricants on page 6-12. Always use the proper ﬂuid. Notice: Use of the incorrect ﬂuid may damage your vehicle and the damages may not be covered by your warranty. Always use the correct ﬂuid listed in Recommended Fluids and Lubricants on page 6-12.

Windshield Washer Fluid What to Use When you need windshield washer ﬂuid, be sure to read the manufacturer’s instructions before use. If you will be operating your vehicle in an area where the temperature may fall below freezing, use a ﬂuid that has sufficient protection against freezing. Adding Washer Fluid Your vehicle has a message that comes on when the washer ﬂuid is low. The message is displayed for 15 seconds at the start of each ignition cycle. When the CHECK WASHER FLUID message is displayed, you will need to add washer ﬂuid to the windshield washer ﬂuid reservoir. See DIC Warnings and Messages on page 3-59 for more information.

Open the cap with the washer symbol on it. Add washer ﬂuid until the tank is full. See Engine Compartment Overview on page 5-12 for reservoir location.

Notice: (cid:129) When using concentrated washer ﬂuid,

follow the manufacturer’s instructions for adding water.

(cid:129) Do not mix water with ready-to-use washer ﬂuid.

Water can cause the solution to freeze and damage your washer ﬂuid tank and other parts of the washer system. Also, water does not clean as well as washer ﬂuid. Fill the washer ﬂuid tank only three-quarters full when it is very cold. This allows for ﬂuid expansion if freezing occurs, which could damage the tank if it is completely full.

(cid:129) Do not use engine coolant (antifreeze) in your windshield washer. It can damage the vehicle’s windshield washer system and paint.

5-35

(cid:129) It is not a good idea to top off the brake ﬂuid. Adding brake ﬂuid will not correct a leak. If ﬂuid is added when the linings are worn, there will be too much ﬂuid when new brake linings are installed. Add or remove brake ﬂuid, as necessary, only when work is done on the brake hydraulic system.

{CAUTION:

If you have too much brake ﬂuid, it can spill on the engine. The ﬂuid will burn if the engine is hot enough. You or others could be burned, and your vehicle could be damaged. Add brake ﬂuid only when work is done on the brake hydraulic system. See “Checking Brake Fluid” in this section.

Refer to the Maintenance Schedule to determine when to check the brake ﬂuid. See Scheduled Maintenance on page 6-4.

Brakes Brake Fluid

The brake master cylinder reservoir is ﬁlled with DOT-3 brake ﬂuid. See Engine Compartment Overview on page 5-12
for the location of the reservoir.

There are only two reasons why the brake ﬂuid level in the reservoir might go down. The ﬁrst is that the brake ﬂuid goes down to an acceptable level during normal brake lining wear. When new linings are put in, the ﬂuid level goes back up. The other reason is that ﬂuid is leaking out of the brake hydraulic system. If it is, you should have the brake hydraulic system ﬁxed, since a leak means that sooner or later the brakes will not work well.

5-36

Checking Brake Fluid The brake ﬂuid can be checked without taking off the cap by looking at the brake ﬂuid reservoir.

Always clean the brake ﬂuid reservoir cap and the area around the cap before removing it. This helps keep dirt from entering the reservoir.

The ﬂuid level should be above MIN. If it is not, have the brake hydraulic system checked to see if there is a leak.

{CAUTION:

With the wrong kind of ﬂuid in the brake hydraulic system, the brakes might not work well. This could cause a crash. Always use the proper brake ﬂuid.

After work is done on the brake hydraulic system, make sure the level is above the MIN but not over the MAX mark. What to Add When you do need brake ﬂuid, use only DOT-3 brake ﬂuid. Use new brake ﬂuid from a sealed container only. See Recommended Fluids and Lubricants on page 6-12.

Notice: (cid:129) Using the wrong ﬂuid can badly damage brake

hydraulic system parts. For example, just a few drops of mineral-based oil, such as engine oil, in the brake hydraulic system can damage brake hydraulic system parts so badly that they will have to be replaced. Do not let someone put in the wrong kind of ﬂuid. If you spill brake ﬂuid on your vehicle’s painted surfaces, the paint ﬁnish can be damaged. Be careful not to spill brake ﬂuid on your vehicle. If you do, wash it off immediately. See Washing Your Vehicle on page 5-102.

5-37

(cid:129) Brake Wear Your vehicle has front disc brakes and could have rear drum brakes or rear disc brakes. Disc brake pads have built-in wear indicators that make a high-pitched warning sound when the brake pads are worn and new pads are needed. The sound can come and go or be heard all the time your vehicle is moving, except when you are pushing on the brake pedal ﬁrmly.

{CAUTION:

The brake wear warning sound means that soon the brakes will not work well. That could lead to an accident. When you hear the brake wear warning sound, have your vehicle serviced.

Notice: Continuing to drive with worn-out brake pads could result in costly brake repair.

Some driving conditions or climates can cause a brake squeal when the brakes are ﬁrst applied or lightly applied. This does not mean something is wrong with the brakes. Properly torqued wheel nuts are necessary to help prevent brake pulsation. When tires are rotated, inspect brake pads for wear and evenly tighten wheel nuts in the proper sequence to torque speciﬁcations in Capacities and Speciﬁcations on page 5-116. If you have rear drum brakes, they do not have wear indicators, but if you ever hear a rear brake rubbing noise, have the rear brake linings inspected immediately. Rear brake drums should be removed and inspected each time the tires are removed for rotation or changing. Drum brakes have an inspection hole to inspect lining wear during scheduled maintenance. When you have the front brake pads replaced, have the rear brakes inspected, too. Brake linings should always be replaced as complete axle sets.

5-38

Brake Pedal Travel See your dealer/retailer if the brake pedal does not return to normal height, or if there is a rapid increase in pedal travel. This could be a sign that brake service might be required. Brake Adjustment Every time you make a brake stop, the brakes adjust for wear. Replacing Brake System Parts The braking system on a vehicle is complex. Its many parts have to be of top quality and work well together if the vehicle is to have really good braking. Your vehicle was designed and tested with top-quality brake parts. When you replace parts of the braking system — for example, when the brake linings wear down and you need new ones put in — be sure you get new approved replacement parts. If you do not, the brakes might not

work properly. For example, if someone puts in brake linings that are wrong for your vehicle, the balance between the front and rear brakes can change — for the worse. The braking performance you have come to expect can change in many other ways if someone puts in the wrong replacement brake parts.

Battery Your vehicle has a maintenance free battery. When it is time for a new battery, see your dealer/retailer for one that has the replacement number shown on the original battery’s label. See Engine Compartment Overview on page 5-12 for battery location. Warning: Battery posts, terminals, and related accessories contain lead and lead compounds, chemicals known to the State of California to cause cancer and reproductive harm. Wash hands after handling.

5-39

Jump Starting If your vehicle’s battery (or batteries) has run down, you may want to use another vehicle and some jumper cables to start your vehicle. Be sure to use the following steps to do it safely.

{CAUTION:

Batteries can hurt you. They can be dangerous because:

(cid:129) They contain acid that can burn you. (cid:129) They contain gas that can explode or

(cid:129) They contain enough electricity to

ignite.

burn you.

If you do not follow these steps exactly, some or all of these things can hurt you.

Vehicle Storage

{CAUTION:

Batteries have acid that can burn you and gas that can explode. You can be badly hurt if you are not careful. See Jump Starting on page 5-40 for tips on working around a battery without getting hurt.

Infrequent Usage: If you drive your vehicle infrequently, remove the black, negative (−) cable from the battery. This will help keep the battery from running down. Extended Storage: For extended storage of your vehicle, remove the black, negative (−) cable from the battery or use a battery trickle charger. This will help maintain the charge of the battery over an extended period of time.

5-40

Ignoring these steps could result in costly

Notice: damage to your vehicle that would not be covered by your warranty. Trying to start your vehicle by pushing or pulling it will not work, and it could damage your vehicle. 1. Check the other vehicle. It must have a 12-volt

battery with a negative ground system.

If the other vehicle’s system is not a 12-volt

Notice: system with a negative ground, both vehicles can

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2008 GMC Sierra Owners Manual