GM Service Manual Online
For 1990-2009 cars only

Fluid level should be checked with the transmission at normal operating temperatures of 45°C to 85°C (113°F to 185°F). The transmission fluid temperature can be verified using a scan tool. Temperature will greatly effect fluid level. If the vehicle is not at normal operating temperature or the proper checking procedures are not followed the fluid level reading could be false causing an improper fluid level adjustment. Improper fluid level may cause poor transmission performance and damage. Wait at least 30 minutes before checking fluid level if vehicle has been driven in the following conditions:

    • When outside temperatures are above 32°C (90°F)
    • In heavy traffic especially in hot weather
    • While pulling a trailer

       Important: When checking transmission fluid level install the transmission fill plug before turning off the engine.

Diagnostic Procedure

  1. START the engine.
  2. Place the transmission in PARK.
  3. Apply the parking brake.
  4. Wait for engine cooling to ambient temperature.
  5. Connect diagnostic tool to vehicle diagnostic system.
  6. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  7. Start the engine.
  8. Shift to all gear positions with brakes applied and return to PARK.
  9. Remove the transmission oil pan fluid fill plug on the side of the oil pan. Engine should be running at idle speed.
  10. Inspect the fluid level:
  11. • The fluid level should be at the lower edge of the plug opening. Adjust fluid level as necessary.
    • Use an oil suction gun to add fluid.
    • Drain or fill the fluid using Dexron®III as needed.

    Important: When checking transmission fluid level install the transmission fill plug before turning off the engine.

  12. Install oil pan fill plug.
  13. Tighten
    Tighten the oil pan fill plug to 45 N·m (33 lb ft).

  14. Lower the vehicle.
  15. Disconnect the diagnostic tool.
  16. Test drive the vehicle.