GM Service Manual Online
For 1990-2009 cars only

The following information covers the checks and services required in order to retain the safety, dependability, and emission control performance of the vehicle.

Ensure any necessary repairs are completed on time. Whenever any fluids or lubricants are added to the vehicle, ensure that the fluids are the proper ones. Refer to Fluid and Lubricant Recommendations .

At Each Fuel Fill

It is important to perform these underhood check at each fuel fill.

Engine Oil Level

Inspect the engine oil level. Add the proper oil if necessary.

In order to select the proper fluids and lubricants, refer to Fluid and Lubricant Recommendations .

Engine Coolant Level

Inspect the engine coolant levels. Add the proper coolant mixture, if necessary. Refer to Fluid and Lubricant Recommendations .

Windshield Washer Fluid Level

Inspect the windshield washer fluid level in the windshield washer reservoir. Add the proper fluid, if necessary. Refer to Fluid and Lubricant Recommendations .

At Least Once a Month

Tire Inflation

Test the tire inflation. Verify that the tires are inflated to the pressures specified on the tire placard located on the driver's door lock pillar. Refer to Tire Inflation Pressure Specifications in General Information.

Cassette Deck Service

Clean the playback heads and the capstan on the cassette deck. Cleaning should be done every 50 hours of tape play. Refer to Cassette Player Care and Cleaning Tape Head and Capstan in Entertainment.

At Least Twice a Year

Restraint System Check

Make sure the seat belt reminder light and all the belts, buckles, latch plates, retractors and anchorages are working properly. Look for any other loose or damaged safety belt system parts. If you see anything that might keep a safety belt system from doing its job, have it repaired. Have any torn or frayed safety belts replaced.

For seat belt diagnosis information, refer to Operational and Functional Checks in Seat Belts.

Also look for any opened or broken Supplemental Inflatable Restraint (SIR) covers. (The SIR system does not need regular maintenance.)

For SIR Diagnosis refer to Diagnostic Starting Point - SIR in SIR.

Wiper Blade Check

Inspect wiper blades for wear or cracking. Replace blade inserts that appear worn, cracked, damaged or that streak or miss areas of the windshield. Refer to Windshield Wiper Blade Replacement in Wipers/Washer System.

Spare Tire Check

At least twice a year, after the monthly inflation check of the spare tire determines that the spare is inflated to the correct tire inflation pressure, make sure that the spare tire is stored securely. Push, pull, and then try to rotate or turn the tire. If it moves, use the wheel wrench to tighten the cable.

Weatherstrip Lubrication

Silicone grease on weatherstrips will make them last longer, seal better, and not stick or squeak. Apply silicone grease with a clean cloth.

During very cold, damp weather more frequent application may be required. Refer to Fluid and Lubricant Recommendations

Automatic Transmission Check

Check the transmission axle fluid level; add if needed.

A fluid loss may indicate a problem. Check the system and repair if needed.

Refer to Transmission Fluid Check .

If fluid was added refer to Fluid Leak Diagnosis .

Check the fluid level in the clutch reservoir. Refer to Fluid and Lubricant Recommendations . A fluid loss in this system could indicate a problem. Have the system inspected and repaired at once.

A fluid loss in this system could indicate a problem. Have the system inspected and repaired at once.

At Least Once a Year

Key Lock Cylinders Service

Lubricate the lock cylinders with the recommended lubricant. Refer to Fluid and Lubricant Recommendations .

Body Lubrication Service

Lubricate all of the following areas:

    • The body door hinges
    • The body hood
    • The fuel door
    • The rear compartment hinges
    • The rear compartment latches and locks
    • The instrument panel compartment hinges
    • The instrument panel compartment latch
    • The instrument panel compartment lock cylinder
    • The console cover hinges and latch
    • The seat hardware

More frequent lubrication may be required when the vehicle is exposed to a corrosive environment. In order to locate the proper lubricant, refer to Fluid and Lubricant Recommendations .

Starter Switch Check

       Caution: When performing this check, the vehicle could move suddenly. Personal injury or property damage may result. Make sure there is enough room around the vehicle, in case the vehicle does move. Do not use the accelerator pedal, and be ready to turn OFF the engine immediately if it starts.

    • Before you start, ensure that you have enough room around the vehicle in case the vehicle jumps suddenly.

       Important: Do not use the accelerator pedal, and be ready to turn off the engine immediately if it starts.

    • Firmly apply both the park brake and the regular brake.
    • Try to start the engine in each gear. The starter should work only in PARK (P) or NEUTRAL (N). If the starter works in any other position, your vehicle needs service.

Automatic Transmission Shift Lock Control Check

    Caution: When performing this check, the vehicle could move suddenly. Personal injury or property damage may result. Make sure there is enough room around the vehicle, in case the vehicle does move. Be ready to apply the regular brake immediately should the vehicle begin to move.

  1. Before you start, be sure you have enough room around the vehicle. It should be parked on a level surface.
  2. Important: Be ready to apply the regular brake immediately if the vehicle begins to move.

  3. Firmly apply the parking brake.
  4. With the engine off, turn the key to the RUN position, but do not start the engine.
  5. Without applying the regular brake, try to move the shift lever out of PARK (P) with normal effort.
  6. If the shift lever moves out of PARK (P), the automatic transmission shift lock control needs service.

Ignition Transmission Lock Check

  1. With the vehicle parked, set the parking brake.
  2. Try to turn the ignition key to LOCK in each shift lever position.
  3. The key should turn to LOCK only when the shift lever is in PARK (P).
  4. The key should come out only in LOCK

Park Brake and Automatic Transmission Park (P) Mechanism Check

    Caution: When performing this check, the vehicle could begin to move. Personal injury or property damage may result. Make sure there is enough room in front of the vehicle, in case the vehicle begins to roll. Be ready to apply the regular brake immediately should the vehicle begin to move.

  1. Ensure that the vehicle is parked on a fairly steep hill with the vehicle facing downhill.
  2. Keep the regular brake firmly engaged while setting the park brake.
  3. Perform the following procedure in order to test the holding ability of the park brake:
  4. • Ensure that the engine is running.
    • Ensure that the transmission is in the NEUTRAL (N) position.
    • Slowly remove foot pressure from the regular brake pedal.
    • Do this until the vehicle is held by the park brake only.
  5. If the parking brake fails to hold the vehicle, repair the system. Refer to Park Brake Adjustment
  6. Perform the following procedure in order to test the holding ability of the PARK (P) mechanism's holding ability:
  7. 5.1. Ensure that the engine is running.
    5.2. Shift to PARK (P).
    5.3. Release all of the brakes.

Underbody Flushing Service

At least every spring, use plain water to flush any corrosive materials from the underbody. Take care to clean thoroughly any areas where mud and other debris can collect.