GM Service Manual Online
For 1990-2009 cars only

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

Make sure any necessary repairs are completed on time. Whenever any fluids or lubricants are added to the vehicle, make sure that they are the proper ones.

At Each Fuel Fill

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

Engine Oil Level

Inspect the engine oil level and add the proper oil if necessary.

Engine Coolant Level

Inspect the engine coolant levels and add DEX-COOL® for the proper coolant mixture, if necessary.

Windshield Washer Fluid Level

Inspect the windshield washer fluid level in the windshield washer reservoir and add the proper fluid, if necessary.

At Least Once a Month

Tire Inflation

Inspect tire inflation. Make sure the tires are inflated to the pressures specified on the Certification/Tire label located on the driver's door lock pillar.

Cassette Desk Service

Clean cassette decks. Cleaning should be done every 50 hours of tape play.

At Least Twice A Year

Wheel Nut Torque

For vehicles with dual wheels, inspect the dual wheel nut torque.

Restraint System Check

Make sure the safety belt reminder light and all of your 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 am safety belt system from doing its job, have it repaired. Have any torn or frayed safety belts replaced.

Also look for any opened or broken air bag coverings, and have them repaired or replaced. (The SIR system does not need regular maintenance).

Wiper Blade Check

Inspect wiper blades for wear or cracking. Replace the blade inserts that appear worn or damaged or that streak or miss areas of the windshield.

Air Cleaner Filter Restriction Indicator Check

Your vehicle has an indicator on the engine that lets you know when the air cleaner filter is dirty and needs to be changed. Inspect indicator at least twice a year or when your oil is changed, whichever occurs first. Inspect your air cleaner filter restriction indicator more often if the vehicle is used in dusty areas or under off road conditions.

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.

Manual Transmission Check (Pickup Models Only)

Inspect the transmission fluid level; add if needed. A fluid loss may indicate a problem. Inspect the system and repair as needed.

Automatic Transmission Check

Inspect the automatic transmission fluid level; add if needed. A fluid loss may indicate a problem. Inspect the system and repair as needed.

Hydraulic Clutch System Check (Pickup Models Only)

Inspect the fluid level in the clutch reservoir. A loss of fluid may 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.

Body Lubrication Service

Lubricate all of the following areas:

    • All body hood hinge pins
    • All body door hinge pins
    • The hood latch assembly
    • The secondary hood latch
    • The pivots
    • The spring anchor
    • The release pawl
    • The rear compartment hinges
    • The outer tailgate handle pivot points
    • The latches
    • The tailgate hinge
    • The tailgate linkage
    • The fuel door hinge
    • The locks
    • The folding seat hardware

More frequent lubrication may be required when exposed to a corrosive environment. In order to locate the proper lubricant.

Starter Switch Check

  1. Before you start, make sure you have enough room around the vehicle.
  2. Important: Do not use the accelerator pedal, and be ready to turn off the engine immediately if it starts.

  3. Firmly apply both the park brake and the regular brake.
  4. On automatic transmission vehicles, 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.
  5. On manual transmission vehicles, put the shift lever in NEUTRAL (N), push the clutch down halfway and try to start the engine. The starter should work only when the clutch is pushed down all the way to the floor. If the starter works when the clutch is not pushed all the way down, your vehicle needs service.

Brake - Transmission Shift Interlock Check

    Caution: When performing this check, the vehicle could begin to move. You or others could be injured and property could be damaged. Make sure there is room in front of the vehicle in case the vehicle begins to roll. Be ready to apply the regular brake at once, should the vehicle begin to move.

  1. Before you start, make sure you have enough room around the vehicle.
  2. Ensure that the vehicle is parked on a level surface.
  3. Important: Be ready to apply the regular brake immediately if the vehicle begins to move.

  4. Firmly apply the park brake. Refer to System Description in Park Brake.
  5. Insure that the engine is off.
  6. Turn the ignition switch to the RUN position, but do not start the engine.
  7. Without applying the regular brake, attempt to move the shift lever out of the PARK (P) with normal effort.
  8. If the shift lever moves out of the PARK (P) position, the vehicle's BTSI needs service.

Ignition Transmission Lock Check

  1. Ensure that the vehicle is parked.
  2. Ensure that the vehicle park brake is set.
  3. Attempt to turn the ignition key to the LOCK position.
  4. • With an automatic transmission, the key should turn to LOCK only when the shift lever is in the PARK (P) position.
    • With an automatic transmission, the key should turn to LOCK only when the shift lever is in the REVERSE (R) position.
  5. On vehicles equipped with a key release button, try to turn the key to the LOCK position without pressing the button.
  6. The key should turn to LOCK only when key release button is pressed.

Follow this procedure to test the park brake and automatic transmission PARK mechanism:

  1. Park on a fairly steep hill, with the vehicle facing downhill.
  2. Keep your foot on the hydraulic brake pedal.
  3. Set the park brake.
  4. In order to inspect the park brake:
  5. 4.1. Start the engine.
    4.2. Place the transmission in NEUTRAL.
    4.3. Slowly remove foot pressure from the hydraulic brake pedal.
  6. In order to inspect the PARK (P) mechanism, follow steps 1-3 above then do the following:
  7. 5.1. Shift to PARK (P).
    5.2. Release all brakes.

Park Brake and Automatic Transmission PARK (P) Mechanism Check

  1. Insure 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. 3.1. Ensure that the engine is running.
    3.2. Ensure that the transmission is in the NEUTRAL (N) position.
    3.3. Slowly remove foot pressure from the regular brake pedal.

    Do this until the vehicle is held by the park brake only.

  5. Perform the following procedure in order to test the holding ability of the PARK (P) mechanism's holding ability:
  6. 4.1. Ensure that the engine is running.
    4.2. Shift to PARK (P).
    4.3. 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.