2004 Chevrolet Silverado Owners Manual

G. Fan. See Cooling System on page5-38.

H. Remote Negative (- ) Terminal (GND). See Jump

Starting on page5-51.

I. Power Steering Fluid Reservoir. See PowerSteering

Fluid on page5-44.

J. Remote Positive (+) Terminal. See JumpStartingon

page5-51.

K. Brake Fluid Reservoir. See Brakesonpage5-47. L. Clutch Fluid Reservoir (If Equipped). See Hydraulic

Clutch on page5-31.

M. Underhood Fuse Block. See FusesandCircuit

Breakers on page5-122.

N. Battery. See Battery on page5-50. O. Windshield Washer Fluid Reservoir. See Windshield

Washer Fluid on page5-45.

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When you lift up the hood on the VORTEC™ 8100 V8 engine you will see the following:

5-16

A. Engine Air Cleaner/Filter. See EngineAir

Cleaner/Filter on page5-22.

B. Coolant Surge Tank. See EngineCoolanton

page5-32.

C. Air Filter Restriction Indicator (If Equipped). See

Engine Air Cleaner/Filter on page5-22.

D. Engine Oil Dipstick. See EngineOilonpage5-17. E. Automatic Transmission Dipstick (If Equipped).

See AutomaticTransmissionFluid(ExceptAllison Transmission®) on page5-24 or Automatic TransmissionFluid(AllisonTransmission®)on page5-27.

F. Engine Oil Fill. See EngineOilonpage5-17. G. Fan. See Cooling System on page5-38. H. Remote Negative (- ) Terminal (GND). See Jump

Starting on page5-51.

I. Remote Positive (+) Terminal. See JumpStartingon

page5-51.

J. Power Steering Fluid Reservoir. See PowerSteering

Fluid on page5-44.

K. Brake Fluid Reservoir. See Brakesonpage5-47. L. Clutch Fluid Reservoir (If Equipped). See Hydraulic

Clutch on page5-31.

M. Underhood Fuse Block. See FusesandCircuit

Breakers on page5-122.

N. Battery. See Battery on page5-50. O. Windshield Washer Fluid Reservoir. See Windshield

Washer Fluid on page5-45.

Engine Oil If your vehicle has a diesel engine, see “Engine Oil” in the Diesel Engine Supplement. If the CHECK OIL LEVEL light appears on the instrument cluster (except vehicles equipped with the 4.3L engine), it means you need to check your engine oil level right away. For more information, see DriverInformation Center (DIC) on page3-54. You should check your engine oil level regularly; this is an added reminder. Checking Engine Oil It is a good idea to check your 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 EngineCompartmentOverviewonpage5-12 for the location of the engine oil dipstick. Turn off the engine and give the oil several minutes to drain back into the oil pan. If you don’t, the oil dipstick might not show the actual level. 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.

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Notice: Do not add too much oil. If your engine has so much oil that the oil level gets above the cross-hatched area that shows the proper operating range, your engine could be damaged.

See EngineCompartment Overviewonpage5-12 for the location of the engine oil fill cap.

All Other Engines

8.1L Engine When to Add Engine Oil If the oil is at or below the cross-hatched area at the tip of the dipstick, then you will need to add at least one quart of oil. But you must use the right kind. This section explains what kind of oil to use. For engine oil crankcase capacity, see CapacitiesandSpecifications on page5-130.

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. What Kind of Engine Oil to Use Look for two things: • GM6094M

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

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• SAE 5W-30

As shown in the viscosity chart, SAE 5W-30 is best for your vehicle. However, if it is going to be 0°F (–18°C) or above and SAE 5W-30 is not available, you may use SAE 10W-30. These numbers on an oil container show its viscosity, or thickness. Do not use other viscosity oils such as SAE 20W-50.

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

You should 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.

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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. GM Goodwrench® oil meets all the requirements for your vehicle. 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 will provide easier cold starting and better protection for your engine at extremely low temperatures. Engine Oil Additives Do not add anything to your oil. The recommended oils with the starburst symbol that meet GM Standard GM6094M are all you will need for good performance and engine protection.

When to Change Engine Oil (GM Oil Life System) 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 message will come on. Change your oil as soon as possible within the next two times you stop for fuel. It is possible that, if you are driving under the best conditions, the oil life system may not indicate that an oil change is necessary for over a year. However, your engine oil and filter must be changed at least once a year and at this time the system must be reset. Your dealer has GM-trained service people who will perform this work using genuine GM parts and reset the system. It is also important to check your oil regularly and keep it at the proper level. If the system is ever reset accidentally, you must change your 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.

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How to Reset the CHANGE ENGINE OIL Message The GM Oil Life System calculates when to change your engine oil and filter based on vehicle use. Anytime your oil is changed, reset the system so it can calculate when the next oil change is required. If a situation occurs where you change your oil prior to a CHANGE ENGINE OIL message being turned on, reset the system. To reset the CHANGE ENGINE OIL message, see “GM Oil Life System” under DICOperationandDisplays onpage3-55 for vehicles equipped with the DIC, or do the following: 1. Turn the ignition key to RUN with the engine off. 2. Fully press and release the accelerator pedal three

times within five seconds. If the OIL LIFE RESET message flashes for 10 seconds, the system is resetting.

3. Turn the key to LOCK. If the CHANGE ENGINE OIL message comes back on when you start your vehicle, the engine oil life system has not reset. Repeat the procedure. If it still does not reset, see your dealer for service.

What to Do with Used Oil Used engine oil contains certain elements that may 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 your used oil, ask your dealer, a service station or a local recycling center for help.

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Engine Air Cleaner/Filter

See EngineCompartment Overviewonpage5-12 for location of engine air cleaner/filter and change indicator (if equipped).

How to Inspect Locate the filter change indicator. When the change indicator turns black or is in the red/orange “change” zone, replace the filter and reset the indicator. To inspect the air cleaner/filter, remove the filter from the vehicle and lightly shake filter to release loose dust and dirt. If the filter remains “caked” with dirt, a new filter is required. To inspect and replace the filter and reset the indicator (if equipped), do the following:

When to Inspect If your vehicle is equipped with a filter change indicator it lets you know when the filter needs to be replaced. Vehicles with a restriction indicator, inspect the air cleaner/filter at every oil change and replace the filter when the indicator tells you to. Vehicles without a change indicator, inspect the air cleaner/filter at every oil change and replace it at the first oil change after 25,000 miles (40 000 km).

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The air cleaner/filter assembly is located on the front corner of the engine compartment on the passenger’s side of the vehicle.

{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 flame 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.

Notice: If the air cleaner/filter is off, a backfire can cause a damaging engine fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner/filter in place when you are driving.

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1. Loosen the screws on the cover of the housing and

lift up the cover.

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

3. Clean the filter sealing surface and the housing. 4. Install the new engine air cleaner/filter. 5. Reinstall the cover and tighten the screws. 6. Reset the filter change indicator, if equipped, by

pressing the top button on the indicator.

Automatic Transmission Fluid (Except Allison Transmission®) When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. Change both the fluid and filter every 50,000 miles (83 000 km) if the vehicle’s GVWR is over 8,600 or if the vehicle is mainly driven under one or more of these conditions: • In heavy city traffic where the outside temperature

regularly reaches 90°F (32°C) or higher.

• In hilly or mountainous terrain. • When doing frequent trailer towing. • Uses such as found in taxi, police or delivery

service.

If your vehicle’s GVWR is not over 8,600 and you do not use your vehicle under any of these conditions, change the fluid and filter every 100,000 miles (166 000 km). See Scheduled Maintenance on page6-4.

How to Check Because this operation can be a little difficult, you may choose to have this done at the dealership 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 part 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: • When outside temperatures are above 90°F (32°C). • At high speed for quite a while. • In heavy traffic – especially in hot weather. • 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).

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

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

See EngineCompartmentOverviewonpage5-12 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’s colder than 50°F (10°C), drive the vehicle in THIRD (3) 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’s 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: • Park your vehicle on a level place. Keep the engine

running.

• With the parking brake applied, place the shift lever

in PARK (P).

• 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 PARK (P).

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

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How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Recommended Fluids and Lubricants on page6-13. Add fluid 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 doesn’t take much fluid, generally less than one pint (0.5 L). Don’toverfill. Notice: We recommend you use only fluid labeled DEXRON® -III, because fluid with that label is made especially for your automatic transmission. Damage caused by fluid other than DEXRON® -III is not covered by your new vehicle warranty. • After adding fluid, recheck the fluid level as

described under HowtoCheck.

• 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 area or cross-hatched area for a hot check. Be sure to keep the dipstick pointed down to get an accurate reading. 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.

4.

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Automatic Transmission Fluid (Allison Transmission®) When to Check and Change A good time to check your automatic transmission fluid level is when the engine oil is changed. Change both the fluid and filter every 25,000 miles (41 500 km) if the vehicle is mainly driven under one or more of these conditions: • In heavy city traffic where the outside temperature

regularly reaches 90°F (32°C) or higher.

• In hilly or mountainous terrain. • When doing frequent trailer towing. • Uses such as found in taxi, police or delivery

service.

If you do not use your vehicle under any of these conditions, change the fluid and filter every 50,000 miles (83 000 km). See Scheduled Maintenance on page6-4.

How to Check Because this operation can be a little difficult, you may choose to have this done at the dealership 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 part 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: • When outside temperatures are above 90°F (32°C). • At high speed for quite a while. • In heavy traffic – especially in hot weather. • While pulling a trailer.

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Checking the Fluid Level Prepare your vehicle as follows: • Park your vehicle on a level place. Keep the engine

running.

• With the parking brake applied, place the shift lever

in PARK (P).

• With your foot on the brake pedal, run the engine

for at least once minute and shift to DRIVE (D). Then shift to NEUTRAL (N) and then REVERSE (R) to fill the hydraulic system. Then, position the shift lever in PARK (P).

• Allow the engine to run at idle (500–800 rpm).

Slowly release the brake pedal.

Then, without shutting off the engine, follow these steps: Cold Check Procedure The purpose of the cold check is to determine if the transmission has enough fluid to be operated safely until a hot check can be made. The fluid level rises as fluid temperature increases. DO NOT fill above the COLD CHECK band if the transmission fluid is below normal operating temperatures. 1. Pull out the dipstick and wipe it with a clean rag or

paper towel.

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

then pull it back out again.

3. Check the fluid level reading. Repeat the check

procedure to verify the reading.

4. If the fluid level is within the COLD CHECK band, the transmission may be operated until the fluid is hot enough to perform a hot check. If the fluid level is not within the COLD CHECK band, add or drain fluid as necessary to bring the level into the middle of the COLD CHECK band.

5. Perform a hot check at the first opportunity after the

normal operating temperature of 160°F (71°C) to 200°F (93°C) is reached.

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

dipstick back in all the way.

Hot Check Procedure The fluid must be hot to ensure an accurate check. The fluid level rises as temperature increases. 1. Operate the transmission in DRIVE (D) range until the normal operating temperature of 160°F (71°C) to 200°F (93°C) is reached.

2. Pull out the dipstick and wipe it with a clean rag or

paper towel.

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

then pull it back out again. Repeat the check procedure to verify the reading.

4. Safe operating level is within the HOT RUN band on the dipstick. The width of the HOT RUN band represents approximately 1.06 quart (1.0 liter) of fluid at normal operating temperature.

5. If the fluid level is not within the HOT RUN band, add or drain fluid as necessary to bring the fluid level to within the HOT RUN band.

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

dipstick back in all the way. Consistency of Readings Always check the fluid level at least twice using the procedures described previously. Consistency (repeatable readings) is important to maintaining proper fluid level. If inconsistent readings persist, check the transmission breather to be sure it is clean and unclogged. If readings are still inconsistent, contact your dealer.

How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Recommended Fluids and Lubricants on page6-13. Add fluid 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 doesn’t take much fluid, generally less than one pint (0.5 L). Don’toverfill. Notice: We recommend you use only fluid labeled DEXRON® -III, because fluid with that label is made especially for your automatic transmission. Damage caused by fluid other than DEXRON® -III is not covered by your new vehicle warranty. • After adding fluid, recheck the fluid level as

described under HowtoCheck.

• When the correct fluid level is obtained, push the

dipstick back in all the way.

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Manual Transmission Fluid When to Check A good time to have it checked is when the engine oil is changed. See your maintenance schedule to find out when to change your transmission fluid. How to Check Because this operation can be a little difficult, you may choose to have this done at your GM dealership service department. If you do it yourself, be sure to follow all the instructions here, or you could get a false reading. 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 part 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. Check the fluid level only when your engine is off, the vehicle is parked on a level place and the transmission is cool enough for you to rest your fingers on the transmission case.

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Then, follow these steps:

5–speed for VORTEC™ 4300 V6 and 4800 V8 Engines Shown, Other Manual

Transmissions Similar

1. Remove the filler plug. 2. Check that the lubricant level is up to the bottom of

the filler plug hole.

3. If the fluid level is good, install the plug and be sure

it is fully seated. If the fluid level is low, add more fluid as described in the next steps.

How to Add Fluid Here’s how to add fluid. Refer to the Maintenance Schedule to determine what kind of fluid to use. See RecommendedFluidsandLubricantsonpage6-13.

1. Remove the filler plug. 2. Add fluid at the filler plug hole. Add only enough

fluid to bring the fluid level up to the bottom of the filler plug hole.

3. Install the filler plug. Be sure the plug is fully

seated.

Hydraulic Clutch The hydraulic clutch linkage in your vehicle is self-adjusting. The clutch master cylinder reservoir is filled with hydraulic clutch fluid. It is not necessary to regularly check clutch fluid unless you suspect there is a leak in the system. Adding fluid won’t correct a leak. A fluid loss in this system could indicate a problem. Have the system inspected and repaired.

When to Check and What to Use

The clutch master cylinder reservoir is located in the rear of the engine compartment on the driver’s side of the vehicle. See EngineCompartment Overviewonpage5-12
for more information on location.

Refer to the Maintenance Schedule to determine how often you should check the fluid level in your clutch master cylinder reservoir and for the proper fluid. See Owner Checks and Services on page6-9 and RecommendedFluidsandLubricantsonpage6-13. How to Check and Add Fluid The proper fluid should be added if the level does not reach the bottom of the diaphragm when it’s in place in the reservoir. See the instructions on the reservoir cap.

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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 5 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 EngineOverheatingon page5-35. A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will: • Give freezing protection down to - 34°F ( - 37°C). • Give boiling protection up to 265°F (129°C). • Protect against rust and corrosion. • 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 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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What to Use Use a mixture of one-half clean,drinkablewater and one-half DEX-COOL® coolant which won’t damage aluminum parts. If you use this coolant mixture, you don’t 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.

Notice: If you use an improper coolant mixture, 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 check your cooling system. Notice: If you use the proper coolant, you do not have to add extra inhibitors or additives which claim to improve the system. These can be harmful. Checking Coolant

The coolant surge tank is located in the engine compartment on the passenger’s side of the vehicle. See Engine CompartmentOverviewon page5-12 for more information on location.

{CAUTION:

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. If your vehicle is equipped with a low coolant sensor, and the LOW COOLANT LEVEL message comes on and stays on, it means you’re low on engine coolant. See “Low Coolant Level” under DICWarningsand Messages on page3-65.

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Adding Coolant If you need more coolant, add the proper DEX-COOL® coolant mixture atthesurgetank, but only when the engine is cool.

{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.

Coolant Surge Tank Pressure Cap

See EngineCompartment Overviewonpage5-12 for more information on location.

The coolant surge tank pressure cap must be fully installed on the coolant surge tank. Notice: If the pressure cap is not tightly installed, coolant loss and possible engine damage may occur. Be sure the cap is properly and tightly secured.

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Engine Overheating You will find a coolant temperature gage on your vehicle’s instrument panel. See Engine Coolant TemperatureGageonpage3-47. In addition, you will find a ENGINE OVERHEATED and a REDUCED ENGINE POWER message in the Driver Information Center on the instrument panel. See DriverInformation Center (DIC) on page3-54. Overheated Engine Protection Operating Mode (V8 Engines Only) If an overheated engine condition exists and the REDUCED ENGINE POWER 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 EngineOilon page5-17.

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If Steam Is Coming From Your Engine

CAUTION:

(Continued)

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 your 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” under EngineOverheatingonpage5-35
for information on driving to a safe place in an emergency.

{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. Just turn it off and get

CAUTION:

(Continued)

Notice: If your engine catches fire because you keep 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” under Engine Overheatingonpage5-35 for information on driving to a safe place in an emergency.

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If you no longer have the overheat warning, you can drive. Just to be safe, drive slower for about 10 minutes. If the warning doesn’t come back on, you can drive normally. If the warning continues, pull over, stop, and park your vehicle right away. If there’s still no sign of steam, push down the accelerator until the engine speed is about twice as fast as normal idle speed for at least three minutes while you’re parked. If you still have the warning, turnoffthe engineandgeteveryoneoutofthevehicle until it cools down. Also, see “Overheated Engine Protection Operating Mode” listed previously in this section. You may decide not to lift the hood but to get service help right away.

If No Steam Is Coming From Your Engine An overheat warning, along with a low coolant condition, can indicate a serious problem. For more information, see DriverInformationCenter(DIC)onpage3-54. If you get an engine overheat warning and don’t have a low coolant condition, but see or hear no steam, the problem may not be too serious. Sometimes the engine can get a little too hot when you: • Climb a long hill on a hot day. • Stop after high speed driving. • Idle for long periods in traffic. • Tow a trailer. See “Driving on Grades” under

Towing a Trailer on page4-71.

If you get the overheat warning with no sign of steam, try this for a minute or so: 1. If you have an air conditioner and it’s on, turn it off. 2. Turn on your heater to full hot at the highest fan

speed and open the window as necessary.

3. If you’re in a traffic jam, shift to NEUTRAL (N);

otherwise, shift to the highest gear while driving – AUTOMATIC OVERDRIVE X or DRIVE (D) for automatic transmissions.

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Cooling System When you decide it’s safe to lift the hood, here’s what you’ll see:

8100 V8 Engines

All Other Engines

A. Coolant Surge Tank B. Coolant Surge Tank Pressure Cap C. Engine Fan If the coolant inside the coolant surge tank is boiling, don’t do anything else until it cools down. The vehicle should be parked on a level surface.

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If there seems to be no leak, start the engine again. The engine cooling fan speed should increase when idle speed is doubled by pushing the accelerator pedal down. If it doesn’t, your vehicle needs service. Turn off the engine. Notice: Engine damage from running your engine without coolant is not covered by your warranty. See “Overheated Engine Protection Operating Mode” in the Index 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 may require changing sooner, at 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.

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

{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.

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CAUTION:

(Continued)

cap when the cooling system, including the coolant surge tank pressure cap, is hot. Wait for the cooling system and coolant surge tank pressure cap to cool if you ever have to turn the pressure cap.

How to Add Coolant to the Coolant Surge Tank for Gasoline Engines If you haven’t found a problem yet, check to see if coolant is visible in the surge tank. If coolant is visible but the coolant level isn’t 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 EngineCoolantonpage5-32 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 coolant surge tank pressure cap — even a little — they can come out at high speed. Never turn the

CAUTION:

(Continued)

5-40

{CAUTION:

{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 a proper coolant.

Notice: In cold weather, water can freeze and crack 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. Park the vehicle on a level surface. You can 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.

2. Turn the pressure cap slowly counterclockwise (left)

about one full turn. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left.

3. Then keep turning the pressure cap slowly, and

remove it.

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4. Then fill the coolant surge tank with the proper

mixture, to the FULL COLD mark.

5. With the coolant surge tank pressure cap off, start

the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fan. By this time, the coolant level inside the coolant surge tank may 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.

5-42

6. Then replace the

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

Engine Fan Noise Your vehicle has a clutched engine cooling fan. When the clutch is engaged, the fan spins faster to provide more air to cool the engine. In most everyday driving conditions, the fan is spinning slower and the clutch is not fully engaged. This improves fuel economy and reduces fan noise. Under heavy vehicle loading, trailer towing and/or high outside temperatures, the fan speed increases as the clutch more fully engages. So you may hear an increase in fan noise. This is normal and should not be mistaken as the transmission slipping or making extra shifts. It is merely the cooling system functioning properly. The fan will slow down when additional cooling is not required and the clutch disengages. You may also hear this fan noise when you start the engine. It will go away as the fan clutch partially disengages.

5-43

Power Steering Fluid

8100 V8 Engine

All Other Engines

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. See EngineCompartmentOverview on page5-12 for reservoir location.

5-44

How to Check Power Steering Fluid Turn the key off, let the engine compartment cool down, wipe the cap and the top of the reservoir clean, then unscrew the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten it. Then 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 RecommendedFluidsandLubricantsonpage6-13. Always use the proper fluid. Failure to use the proper fluid can cause leaks and damage hoses and seals.

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. See Engine CompartmentOverviewonpage5-12 for reservoir location.

5-45

Adding Washer Fluid Your vehicle has a low washer fluid 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.

The windshield washer fluid reservoir is located in the engine compartment toward the front of the vehicle on the driver’s side.

Open the cap with the washer symbol on it. Add washer fluid until the tank is full.

Notice: • When using concentrated washer fluid, follow

the manufacturer’s instructions for adding water.

• 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 your washer fluid tank only three-quarters

full when it is very cold. This allows for expansion if freezing occurs, which could damage the tank if it is completely full.

• Do not use engine coolant (antifreeze) in your windshield washer. It can damage your washer system and paint.

5-46

Brakes Brake Fluid Your brake master cylinder reservoir is filled with DOT-3
brake fluid. See EngineCompartmentOverviewon page5-12 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 system. If it is, you should have your brake system fixed, since a leak means that sooner or later your brakes will not work well, or will not work at all. So, it is not a good idea to “top off” your brake fluid. Adding brake fluid will not correct a leak. If you add fluid when your linings are worn, then you will have too much fluid when you get new brake linings. You should 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 your brake fluid. See ScheduledMaintenance on page6-4.

5-47

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 page6-13. Always clean the brake fluid reservoir cap and the area around the cap before removing it. This will help keep dirt from entering the reservoir.

{CAUTION:

With the wrong kind of fluid in your brake system, your brakes may not work well, or they may not even work at all. This could cause a crash. Always use the proper brake fluid.

Checking Brake Fluid You can check the brake fluid without taking off the cap.

Just look at the brake fluid reservoir. The fluid level should be above MIN. If it is not, have your brake system checked to see if there is a leak. After work is done on the brake hydraulic system, make sure the level is above the MIN but not over the MAX mark.

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Notice: • Using the wrong fluid can badly damage brake system parts. For example, just a few drops of mineral-based oil, such as engine oil, in your brake system can damage brake 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 Appearance Careonpage5-112.

Brake Wear Your vehicle has four-wheel 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 may 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 your 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 may cause a brake squeal when the brakes are first applied or lightly applied. This does not mean something is wrong with your 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 GM torque specifications. Brake linings should always be replaced as complete axle sets.

5-49

Brake Pedal Travel See your dealer 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 of brake trouble. Brake Adjustment Every time you make a brake stop, your disc 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 GM brake parts. When you replace parts of your braking system — for example, when your brake linings wear down and you need new ones put in — be sure you get new approved GM replacement parts. If you do not, your brakes may no longer work properly.

For example, if someone puts in brake linings that are wrong for your vehicle, the balance between your 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 new vehicle comes with a maintenance free ACDelco® battery. When it is time for a new battery, get one that has the replacement number shown on the original battery’s label. We recommend an ACDelco® battery. See EngineCompartmentOverviewon page5-12 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.

5-50

Vehicle Storage If you are not going to drive your vehicle for 25 days or more, remove the black, negative (- ) cable from the battery. This will help keep your battery from running down.

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

{CAUTION:

{CAUTION:

Batteries have acid that can burn you and gas that can explode. You can be badly hurt if you are not careful. See JumpStartingon page5-51 for tips on working around a battery without getting hurt.

Contact your dealer to learn how to prepare your vehicle for longer storage periods. Also, for your audio system, see Theft-Deterrent Feature on page3-126.

Batteries can hurt you. They can be dangerous because:

• They contain acid that can burn you. • They contain gas that can explode or

• 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.

Notice: Ignoring these steps could result in costly 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.

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Notice: If the other vehicle’s system is not a 12-volt system with a negative ground, both vehicles can be damaged. Only use vehicles with 12-volt systems with negative grounds to jump start your vehicle.

If you have a vehicle with a diesel engine with two batteries (or more), you should know before you begin that, especially in cold weather, you may not be able to get enough power from a single battery in another vehicle to start your diesel engine. If your vehicle has more than one battery, use the battery that’s closer to the starter – this will reduce electrical resistance.

2. Get the vehicles close enough so the jumper cables can reach, but be sure the vehicles aren’t touching each other. If they are, it could cause a ground connection you don’t want. You wouldn’t be able to start your vehicle, and the bad grounding could damage the electrical systems. To avoid the possibility of the vehicles rolling, set the parking brake firmly on both vehicles involved in the jump start procedure. Put an automatic transmission in PARK (P) or a manual transmission in NEUTRAL before setting the parking brake. If you have a four-wheel-drive vehicle, be sure the transfer case is in a drive gear not in NEUTRAL.

Notice: If you leave your radio or other accessories on during the jump starting procedure, they could be damaged. The repairs would not be covered by your warranty. Always turn off your radio and other accessories when jump starting your vehicle. 3. Turn off the ignition on both vehicles. Unplug

unnecessary accessories plugged into the cigarette lighter or accessory power outlets. Turn off the radio and all lamps that aren’t needed. This will avoid sparks and help save both batteries. And it could save your radio!

4. Open the hoods and locate the positive (+) and

negative (- ) terminal locations of the other vehicle. Your vehicle has a remote positive (+) jump starting terminal and a remote negative (- ) jump starting terminal. You should always use these remote terminals instead of the terminals on the battery. The remote positive (+) terminal is located behind a red plastic cover, if equipped, near the engine accessory drive bracket. To uncover the remote positive (+) terminal, open the red plastic cover, if equipped. The remote negative (- ) terminal is located on the engine drive bracket on all V8 and diesel engines, and on the thermostat housing on the 8.1L engine. On V8 engines it is marked “GND.”

5-52

On V6 engines the remote negative (- ) terminal is located on a tab attached to the engine accessory drive bracket where it is marked “GND.” See EngineCompartmentOverviewonpage5-12
for more information on location.

{CAUTION:

Using a match near a battery can cause battery gas to explode. People have been hurt doing this, and some have been blinded. Use a flashlight if you need more light. Be sure the battery has enough water. You do not need to add water to the ACDelco® battery installed in your new vehicle. But if a battery has filler caps, be sure the right amount of fluid is there. If it is low, add water to take care of that first. If you do not, explosive gas could be present. Battery fluid contains acid that can burn you. Do not get it on you. If you accidentally get it in your eyes or on your skin, flush the place with water and get medical help immediately.

{CAUTION:

Fans or other moving engine parts can injure you badly. Keep your hands away from moving parts once the engine is running.

5. Check that the jumper cables don’t have loose or

missing insulation. If they do, you could get a shock. The vehicles could be damaged too. Before you connect the cables, here are some basic things you should know. Positive (+) will go to positive (+) or a remote positive terminal (+) if the vehicle has one. Negative (- ) will go to a heavy, unpainted metal engine part or a remote negative (- ) terminal if the vehicle has one. Don’t connect positive (+) to negative (- ) or you’ll get a short that would damage the battery and maybe other parts too. And don’t connect the negative (- ) cable to the negative (- ) terminal on the dead battery because this can cause sparks. On vehicles equipped with dual batteries, make all battery connections to the remote positive (+) and remote negative (- ) terminals.

5-53

6. Connect the red

positive (+) cable to the positive (+) terminal of the vehicle with the dead battery. Use a remote positive (+) terminal if the vehicle has one.

8. Now connect the black

negative (- ) cable to the negative (- ) terminal of the good battery. Use a remote negative (- ) terminal if the vehicle has one. The vehicle’s remote negative (–) terminal is marked GND.

7. Don’t let the other end touch metal. Connect it to the positive (+) terminal of the good battery. Use a remote positive (+) terminal if the vehicle has one.

9. Don’t let the other end touch anything until the next

step. The other end of the negative (- ) cable doesn’t go to the dead battery. It goes to a heavy unpainted metal engine part of the vehicle with the dead battery, or to a remote negative (–) terminal if the vehicle has one.

5-54

10. Connect the other end of the negative (- ) cable to the remote negative (- ) terminal, marked GND, on the vehicle with the dead battery.

11. Now start the vehicle with the good battery and run

the engine for a while.

12. Try to start the vehicle that had the dead battery. If

it won’t start after a few tries, it probably needs service.

Notice: If the jumper cables are removed in the wrong order, electrical shorting may occur and damage the vehicle. The repairs would not be covered by your warranty. Remove the jumper cables in the correct order, making sure that the cables do not touch each other or other metal.

V8 Engine

8.1L Engine

V8 Engine, Diesel

Similar

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To disconnect the jumper cables from both vehicles do the following: 1. Disconnect the black negative (- ) cable from the

vehicle that had the bad battery.

2. Disconnect the black negative (- ) cable from the

vehicle with the good battery.

3. Disconnect the red positive (+) cable from the

vehicle with the good battery.

4. Disconnect the red positive (+) cable from the other

vehicle.

5. Return the positive (+) remote terminal cover to its

original position.

Jumper Cable Removal

A. Heavy, Unpainted Metal Engine Part or Remote

Negative (- ) Terminal

B. Good Battery or Remote Positive (+) and Remote

Negative (- ) Terminals

C. Dead Battery or Remote Positive (+) Terminal

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How to Check Lubricant

All-Wheel Drive Lubricant checks in this section also apply to these vehicles. However, there are two additional systems that need lubrication. Transfer Case When to Check Lubricant Refer to the Maintenance Schedule to determine how often to check the lubricant. See Scheduled Maintenance on page6-4.

AWD Transfer Case (A) Fill Plug (B) Drain Plug

To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. Use care not to overtighten the plug. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See RecommendedFluids and Lubricants on page6-13.

5-57

Rear Axle When to Check Lubricant It is not necessary to regularly check rear axle fluid unless you suspect there is a leak or you hear an unusual noise. A fluid loss could indicate a problem. Have it inspected and repaired.. How to Check Lubricant

The proper level for the 1500 Series is from 5/8 inch to 1 5/8 inch (15 mm to 40 mm) below the bottom of the filler plug hole. The proper level for the 1500 HD Series, 2500 Series, 2500 HD, and 3500 Series is from 0 to 1/2 inch (0 to 13 mm) below the bottom of the filler plug hole. The proper level for the 1500 and 2500 Series vehicles with QUADRASTEER™ (4 Wheel Steer) is from 0 to 1/4 inch (0 to 6 mm) below the filler plug hole. Add only enough fluid to reach the proper level. What to Use To determine what kind of lubricant to use see RecommendedFluidsandLubricantsonpage6-13. Four-Wheel Drive Lubricant checks in this section also apply to these vehicles. However, there are two additional systems that need lubrication.

1500 Series Shown, 2500 Series Similar

To get an accurate reading, the vehicle should be on a level surface.

5-58

Transfer Case When to Check Lubricant It is not necessary to regularly check transfer case fluid unless you suspect there is a leak or you hear an unusual noise. A fluid loss could indicate a problem. Have it inspected and repaired. How to Check Lubricant

Manual Transfer Case

Automatic Transfer Case

To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the filler plug hole, you’ll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. Use care not to overtighten the plug.

5-59

How to Check Lubricant

When to Change Lubricant Refer to the Maintenance Schedule to determine how often to change the lubricant. See Scheduled Maintenance on page6-4. What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See RecommendedFluids and Lubricants on page6-13. Front Axle When to Check Lubricant It is not necessary to regularly check front axle fluid unless you suspect there is a leak or you hear an unusual noise. A fluid loss could indicate a problem. Have it inspected and repaired.

To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the filler plug hole, you may need to add some lubricant.

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When the differential is cold, add enough lubricant to raise the level to 0 to 3/8 inch (9.5 mm) below the filler plug hole. When the differential is at operating temperature (warm), add enough lubricant to raise the level to the bottom of the filler plug hole. What to Use To determine what kind of lubricant to use see RecommendedFluidsandLubricantsonpage6-13. Noise Control System

Tampering with Noise Control System Prohibited The following information relates to compliance with federal noise emission standards for vehicles with a Gross Vehicle Weight Rating (GVWR) of more than 10,000 lbs (4 536 kg). The Maintenance Schedule provides information on maintaining the noise control system to minimize degradation of the noise emission control system during the life of your vehicle. The noise control system warranty is given in your warranty booklet.

These standards apply only to vehicles sold in the United States. Federal law prohibits the following acts or the causing thereof: 1. The removal or rendering inoperative by any

person, other than for purposes of maintenance, repair or replacement, of any device or element of design incorporated into any new vehicle for the purpose of noise control, prior to its sale or delivery to the ultimate purchaser or while it is in use; or

2. The use of the vehicle after such device or element of design has been removed or rendered inoperative by any person.

Among those acts presumed to constitute tampering are the acts listed below. Insulation: • Removal of the noise shields or any underhood

insulation.

Engine: • Removal or rendering engine speed governor (if

equipped) inoperative so as to allow engine speed to exceed manufacturer specifications.

5-61

Fan and Drive: • Removal of fan clutch (if equipped) or rendering

clutch inoperative.

• Removal of the fan shroud (if equipped). Air Intake: • Removal of the air cleaner silencer. • Modification of the air cleaner. Exhaust: • Removal of the muffler and/or resonator. • Removal of the exhaust pipes and exhaust pipe

clamps.

Bulb Replacement For any bulb changing procedure not listed in this section, contact your dealer. See ReplacementBulbsonpage5-71 for the proper types of bulbs to use.

Halogen Bulbs

{CAUTION:

Halogen bulbs have pressurized gas inside and can burst if you drop or scratch the bulb. You or others could be injured. Be sure to read and follow the instructions on the bulb package.

5-62

Headlamps

1. If your vehicle is equipped with two pins, remove

the two pins on the top of the headlamp assembly. To remove the pins, turn the outer pin outward and pull it straight up. To remove the inner pin, turn it in and pull it straight up.

If your vehicle has one pin on the headlamp assembly, remove the pin. To remove the pin, turn the pin up and pull it out straight out.

5-63

Front Turn Signal, Sidemarker and Daytime Running Lamps

A. Sidemarker Lamp B. Retainer Clip C. Front Turn Signal Lamp D. Daytime Running Lamp 1. Remove the headlamp assembly as mentioned

previously.

2. Press the retainer clip, located behind the turn

signal housing, towards the outside of the vehicle. 3. Pull the turn signal housing out from the vehicle. 4. Press the locking release lever, turn the bulb socket

counterclockwise and remove the socket from the turn signal housing.

A. Low-Beam Headlamp B. High-Beam Headlamp

2. Pull the headlamp assembly out. 3. Unplug the electrical connector. 4. Turn the old bulb counterclockwise and remove it

from the headlamp assembly.

5. Put the new bulb into the assembly and turn it clockwise until it is tight. Use care not to touch the bulb with your fingers or hands.

6. Plug in the electrical connector. 7. Put the headlamp assembly back into the vehicle. Install and tighten the two pins. If your vehicle has one pin, install it and turn it into the locking feature.

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5. Remove the old bulb from the bulb socket. 6. Put the new bulb into the bulb socket. Use care not

to touch the bulb with your fingers or hands.

7. Put the bulb socket into the turn signal housing and

turn it clockwise until it locks.

8. Reinstall the turn signal housing onto the vehicle, placing the hook and posts on the inner side into the alignment holes, and the outer side into the retainer bracket. Push until you hear a click.

9. Reinstall the headlamp assembly.

Roof Marker Lamps

1. Remove the two screws and lift off the lens.

2. Remove the six screws on the center roof marker

lamps.

3. Turn the old bulb counterclockwise to remove it

from the socket.

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4. Put a new bulb into the

socket and turn clockwise until it locks in place.

5. Reinstall the lens and tighten the screws.

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Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp

1. Remove the screws and lift off the lamp assembly.

A. Cargo Lamps B. Center High-Mounted Stoplamps

2. Remove the CHMSL bulb holder back plate from

the housing by pressing the release tabs.

3. Remove the CHMSL bulb by pulling the bulb

straight out from the holder back plate. Remove a cargo bulb by turning the socket counterclockwise and pulling the bulb straight out.

5-67

Pickup Box Identification and Fender Marker Lamps 1. Remove the screws and lamp assembly. 2. Unplug the lamp assembly harness. 3. Gently pry the individual lamp from the lamp

housing.

4. Unplug the lamp. 5. Plug in a new lamp and snap it into the housing. 6. Reinstall the lamp housing.

4.

If a CHMSL bulb is replaced, put the new bulb into the socket and press it in until it is tight. If a cargo lamp is replaced, put a new cargo lamp bulb into the socket and press it in until it is tight before turning the socket counterclockwise.

5. Put the bulb holder back plate into the lamp

housing.

6. Reinstall the lamp assembly and tighten the screws.

5-68

Taillamps 1. Open the tailgate.

2. Remove the two rear

lamp assembly screws near the tailgate latch and pull out the lamp assembly.

Your vehicle may have one of the following taillamp assemblies:

A. Stoplamp B. Turn Signal C. Back-up Lamp

A. Stoplamp B. Turn Signal Lamp C. Back-up Lamp D. Side Marker Lamp

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3. Press the release tab,

if equipped, and turn the bulb socket counterclockwise to remove it from the taillamp housing.

4. Pull the old bulb straight out from the socket. 5. Press a new bulb into the socket and turn the socket

clockwise into the taillamp housing.

6. Reinstall the rear lamp assembly. 7. Close the tailgate.

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Taillamps (Chassis Cab Models)

Replacement Bulbs

A. Turn Signal Lamp B. Stoplamp C. Back-up Lamp

1. Using your hands, peel the rubber seal away from

the lens.

2. Lift the lens off the lamp assembly. 3. Pull the old bulb straight out from the socket. 4. Put a new bulb into the socket and press it in until it

is tight.

5. Reinstall the lens and the lens seal.

Bulb Number

194

3457A

9006
9005
4114K

Exterior Lamp Low-Beam Headlamps High-Beam Headlamp Daytime Running Lamps (DRL) Front Roof Marker Lamps Front Parking and Turn Lamp Rear Marker Lamp, Taillamp and Stop Lamp** Taillamp and Stop Lamp** Sidemarker Lamp (If Equipped) Rear Turn Lamp Rear Turn Lamp ** Back-up Lamp Back-up Lamp** Center High-Mounted Stoplamp Cargo Lamp Fender Marker Lamps * For any Bulb not listed here, contact your dealer. ** Chassis Cab Models

1157
194
3157
1156
3157
1156
912
912
194

3157

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Windshield Wiper Blade Replacement Windshield wiper blades should be inspected at least twice a year for wear and cracking. See Scheduled Maintenance on page6-4 for more information. Replacement blades come in different types and are removed in different ways. For proper type and length, see NormalMaintenanceReplacementPartson page6-16.

5-72

To replace the windshield wiper blade assembly do the following: 1. Lift the wiper arm and turn the blade until it is

facing away from the windshield.

2. Push the release lever and slide the wiper assembly

toward the driver’s side of the vehicle.

3. Install a new blade by reversing Steps 1 and 2.

Tires Your new vehicle comes with high-quality tires made by a leading tire manufacturer. If you ever have questions about your tire warranty and where to obtain service, see your GM Warranty booklet for details. For additional information refer to the tire manufacturer’s booklet included with your vehicle’s Owner’s Manual.

{CAUTION:

Poorly maintained and improperly used tires are dangerous.

• Overloading your tires can cause

overheating as a result of too much friction. You could have an air-out and a serious accident. See “Loading Your Vehicle” in the Index.

CAUTION:

(Continued)

CAUTION:

(Continued)

• Underinflated tires pose the same danger as overloaded tires. The resulting accident could cause serious injury. Check all tires frequently to maintain the recommended pressure. Tire pressure should be checked when your tires are cold.

• Overinflated tires are more likely to be cut,

punctured or broken by a sudden impact — such as when you hit a pothole. Keep tires at the recommended pressure.

• Worn, old tires can cause accidents. If

your tread is badly worn, or if your tires have been damaged, replace them.

Tire Sidewall Labeling Useful information about a tire is molded into the sidewall. The following illustrations are examples of a typical P-Metric and a LT-Metric tire sidewall.

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(A) Tire Size Code: The tire size code is a combination of letters and numbers used to define a particular tire’s width, height, aspect ratio, construction type and service description. See the “Tire Size Code” illustration later in this section for more detail.

(B) Tire Performance Criteria Specification (TPC Spec): Original equipment tires designed to GM’s specific tire performance criteria have a TPC specification code molded onto the sidewall. GM’s TPC specifications meet or exceed all federal safety guidelines.

(C) Department of Transportation (DOT): The Department of Transportation (DOT) code indicates that the tire is in compliance with the U.S. Department of Transportation Motor Vehicle Safety Standards.

(D) Tire Identification Number (TIN): The letters and numbers following DOT code are the Tire Identification Number (TIN). The TIN shows the manufacturer and plant code, tire size, and date the tire was manufactured. The TIN is molded onto both sides of the tire, although only one side may have the date of manufacture.

P-Metric Tire

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(E) Tire Ply Material: The type of cord and number of plies in the sidewall and under the tread.

(F) Uniform Tire Quality Grading (UTQG): Tire manufacturers are required to grade tires based on three performance factors: treadwear, traction and temperature resistance. For more information, see Uniform Tire Quality Grading on page5-87.

(G) Maximum Cold Inflation Load Limit: Maximum load that can be carried and the maximum pressure needed to support that load. For information on recommended tire pressure see Inflation-TirePressure onpage5-81 and LoadingYourVehicleonpage4-57.

LT-Metric Tire

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(A) Tire Size: The tire size code is a combination of letters and numbers used to define a particular tire’s width, height, aspect ratio, construction type and service description. See the “Tire Size” illustration later in this section for more detail.

(B) Tire Performance Criteria Specification (TPC Spec): Original equipment tires designed to GM’s specific tire performance criteria have a TPC specification code molded onto the sidewall. GM’s TPC specifications meet or exceed all federal safety guidelines.

(C) Dual Tire Maximum Load: Maximum load that can be carried and the maximum pressure needed to support that load when used in a dual configuration. For information on recommended tire pressure see Inflation-TirePressureonpage5-81 and LoadingYour Vehicle on page4-57.

(D) Department of Transportation (DOT): The Department of Transportation (DOT) code indicates that the tire is in compliance with the U.S. Department of Transportation Motor Vehicle Safety Standards.

(E) Tire Identification Number (TIN): The letters and numbers following DOT code are the Tire Identification Number (TIN). The TIN shows the manufacturer and plant code, tire size, and date the tire was manufactured. The TIN is molded onto both sides of the tire, although only one side may have the date of manufacture.

(F) Tire Ply Material: The type of cord and number of plies in the sidewall and under the tread.

(G) Single Tire Maximum Load: Maximum load that can be carried and the maximum pressure needed to support that load when used as a single. For information on recommended tire pressure see Inflation-TirePressureonpage5-81 and LoadingYour Vehicle on page4-57.

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Tire Size The following examples show the different parts of a tire size.

Passenger (P-Metric) Tire

(A) Passenger (P-Metric) Tire: The United States version of a metric tire sizing system. The letter “P” as the first character in the tire size means a passenger vehicle tire engineered to standards set by the U.S. Tire and Rim Association.

(B) Tire Width: The three-digit number indicates the tire section width in millimeters from sidewall to sidewall.

(C) Aspect Ratio: A two-digit number that indicates the tire height-to-width measurements. For example, if the tire size aspect ratio is “75,” as shown in item “C” of the illustration, it would mean that the tire’s sidewall is 75% as high as it is wide.

(D) Construction Code: A letter code is used to indicate the type of ply construction in the tire. The letter “R” means radial ply construction; the letter “D” means diagonal or bias ply construction; and the letter “B” means belted-bias ply construction.

(E) Rim Diameter: Diameter of the wheel in inches.

(F) Service Description: The service description indicates the load range and speed rating of a tire. The load index can range from 1 to 279. Speed ratings range from “A” to “Z”.

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(D) Construction Code: A letter code is used to indicate the type of ply construction in the tire. The letter “R” means radial ply construction; the letter “D” means diagonal or bias ply construction; and the letter “B” means belted-bias ply construction.

(E) Rim Diameter: Diameter of the wheel in inches.

(F) Service Description: The service description indicates the load range and speed rating of a tire. The load index can range from 1 to 279. Speed ratings range from “A” to “Z”. The light truck tire size example above shows dual or single tire configurations. Tire Terminology and Definitions

Air Pressure: The amount of air inside the tire pressing outward on each square inch of the tire. Air pressure is expressed in pounds per square inch (psi) or kilopascal (kPa).

Accessory Weight: This means the combined weight of optional accessories. Some examples of optional accessories are, automatic transmission, power steering, power brakes, power windows, power seats, and air conditioning.

Light Truck (LT-Metric) Tire

(A) Light Truck (LT-Metric) Tire: The United States version of a metric tire sizing system. The letter “LT” as the first two characters in the tire size means a light truck tire engineered to standards set by the U. S. Tire and Rim Association.

(B) Tire Width: The three-digit number indicates the tire section width in millimeters from sidewall to sidewall.

(C) Aspect Ratio: A two-digit number that indicates the tire height-to-width measurements. For example, if the tire size aspect ratio is “75,” as shown in item “C” of the illustration, it would mean that the tire’s sidewall is 75% as high as it is wide.

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Aspect Ratio: The relationship of a tire’s height to its width.

GVWR: Gross Vehicle Weight Rating, see Loading Your Vehicle on page4-57.

Belt: A rubber coated layer of cords that is located between the plies and the tread. Cords may be made from steel or other reinforcing materials.

Bead: The tire bead contains steel wires wrapped by steel cords that hold the tire onto the rim.

Bias Ply Tire: A pneumatic tire in which the plies are laid at alternate angles less than 90 degrees to the centerline of the tread.

Cold Inflation Pressure: The amount of air pressure in a tire, measured in pounds per square inch (psi) or kilopascals (kPa) before a tire has built up heat from driving. See Inflation-TirePressureonpage5-81.

Curb Weight: This means the weight of a motor vehicle with standard and optional equipment including the maximum capacity of fuel, oil and coolant, but without passengers and cargo.

DOT Markings: A code molded into the sidewall of a tire signifying that the tire is in compliance with the U.S. Department of Transportation motor vehicle safety standards. The DOT code includes the Tire Identification Number (TIN), an alphanumeric designator which can also identify the tire manufacturer, production plant, brand and date of production.

GAWR FRT: Gross Axle Weight Rating for the front axle, see Loading Your Vehicle on page4-57.

GAWR RR: Gross Axle Weight Rating for the rear axle, see Loading Your Vehicle on page4-57.

Intended Outboard Sidewall: The side of an asymmetrical tire, that must always face outward when mounted on a vehicle.

Kilopascal (kPa): The metric unit for air pressure. There are 6.9 kPa’s to one psi.

Light Truck (LT-Metric) Tire: A tire used on light duty trucks and some multipurpose passenger vehicles.

Load Index: An assigned number ranging from 1 to 279
that corresponds to the load carrying capacity of a tire.

Maximum Inflation Pressure: The maximum air pressure to which a cold tire may be inflated. The maximum air pressure is molded onto the sidewall.

Maximum Load Rating: The load rating for a tire at the maximum permissible inflation pressure for that tire.

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Maximum Loaded Vehicle Weight: The sum of curb weight; accessory weight; vehicle capacity weight; and production options weight. Normal Occupant Weight: The number of occupants a vehicle is designed to seat multiplied by 150 pounds (68 kg). See LoadingYourVehicleonpage4-57. Occupant Distribution: Designated seating positions. Outward Facing Sidewall: The side of a asymmetrical tire that has a particular side that faces outward when mounted on a vehicle. The side of the tire that contains a whitewall, bears white lettering or bears manufacturer, brand and or model name molding that is higher or deeper than the same moldings on the other sidewall of the tire. Passenger (P-Metric) Tire: A tire used on passenger cars and some light duty trucks and multipurpose vehicles. Recommended Inflation Pressure: Vehicle manufacturer’s recommended tire inflation pressure and shown on the tire placard. See Inflation-TirePressure onpage5-81 and LoadingYourVehicleonpage4-57. Radial Ply tire: A pneumatic tire in which the ply cords that extend to the beads are laid at 90 degrees to the centerline of the tread. Rim: A metal support for a tire and upon which the tire beads are seated.

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Sidewall: The portion of a tire between the tread and the bead.

Speed Rating: An alphanumeric code assigned to a tire indicating the maximum speed at which a tire can operate.

Traction: The friction between the tire and the road surface. The amount of grip provided.

Tread: The portion of a tire that comes into contact with the road.

Treadwear Indicators: Narrow bands, sometimes called “wear bars,” that show across the tread of a tire when only 2/32 inch of tread remains. See WhenIt Is Time for New Tires on page5-85.

UTQGS: Uniform Tire Quality Grading Standards, a tire information system that provides consumers with ratings for a tire’s traction, temperature and treadwear. Ratings are determined by tire manufacturers using government testing procedures. The ratings are molded into the sidewall of the tire. See UniformTireQuality Grading on page5-87.

Vehicle Capacity Weight: The number of designated seating positions multiplied by 150 lbs. (68 kg) plus the rated cargo load. See LoadingYourVehicle on page4-57.

Vehicle Maximum Load on the Tire: Load on an individual tire due to curb weight, accessory weight, occupant weight and cargo weight. Vehicle Placard: A label permanently attached to a vehicle showing the original equipment tire size and recommended inflation pressure. See LoadingYour