GM Service Manual Online
For 1990-2009 cars only

Starter Switch Check

Caution: When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured.

  1. Before you start, be sure you have enough room around the vehicle.
  2. Firmly apply both the parking brake and the regular brake. See Parking Brake .
  3. Do not use the accelerator pedal, and be ready to turn off the engine immediately if it starts.

  4. On automatic transmission vehicles, try to start the engine in each gear. The vehicle should start only in PARK (P) or NEUTRAL (N). If the vehicle starts in any other position, contact your dealer/retailer for service.
  5. On manual transmission vehicles, put the shift lever in NEUTRAL, push the clutch pedal down halfway, and try to start the engine. The vehicle should start only when the clutch pedal is pushed down all the way to the floor. If the vehicle starts when the clutch pedal is not pushed all the way down, contact your dealer/retailer for service.

Automatic Transmission Shift Lock Control System Check

Caution: When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured.

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

  4. With the engine off, turn the ignition to ON/RUN, but do not start the engine. Without applying the regular brake, try to move the shift lever out of PARK (P) with normal effort. If the shift lever moves out of PARK (P), contact your dealer/retailer for service.

Ignition Transmission Lock Check

While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position.

    • With an automatic transmission, the ignition should turn to LOCK/OFF only when the shift lever is in PARK (P). The ignition key should come out only in LOCK/OFF.
    • With a manual transmission, the ignition key should come out only in LOCK/OFF.

Turn the steering wheel to the left and to the right. It should only lock when turned to the right. Contact your dealer/retailer if service is required.

Parking Brake and Automatic Transmission Park (P) Mechanism Check

Caution: When you are doing 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 it begins to roll. Be ready to apply the regular brake at once should the vehicle begin to move.

Park on a fairly steep hill, with the vehicle facing downhill. Keeping your foot on the regular brake, set the parking brake.

    • To check the parking brake's holding ability: With the engine running and transmission in NEUTRAL (N), slowly remove foot pressure from the regular brake pedal. Do this until the vehicle is held by the parking brake only.
    • To check the PARK (P) mechanism's holding ability: With the engine running, shift to PARK (P). Then release the parking brake followed by the regular brake.

Contact your dealer/retailer if service is required.

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.