GM Service Manual Online
For 1990-2009 cars only

Description

Lack of, or too much, automatic transmission fluid (ATF); contaminated with water, engine coolant or a different type of ATF.

Procedure

Inspect ATF Level

  1. Park the vehicle on a flat level surface.
  2. Confirm that the ATF temperature is at normal operating range of 60-70°C (140-158°F).
  3. Important: ATF level increases as it heats up. Therefore, inspect the ATF level at its normal operating temperature, on a flat level surface, to ensure accuracy.

  4. With the engine at a base idle, apply the service brakes and then slowly move the automatic transmission gearshift selector through all ranges, returning to the PARK position.
  5. Remove the fluid level indicator and wipe the fluid level indicator with a clean, lint free cloth. Reinsert the fluid level indicator into the fluid level indicator tube making sure that the fluid level indicator is fully seated into the fluid level indicator tube.
  6. Remove the fluid level indicator and verify that the ATF level is within the "HOT" level markings as indicated on the fluid level indicator.
  7. Important: If the AFT level on the fluid level indicator is different from front to back when inspecting, add or remove ATF until the lower of the two readings is within the correct level.

  8. Adjust the ATF level as necessary, by adding or draining ATF, in order to obtain the desired reading in the "HOT" range on the fluid level indicator.

Inspect ATF Condition

  1. Inspect the condition of the ATF in order to make sure that the following signs are NOT present:
  2. • Mixing of metal particles and or excessive disc friction material
    • Burnt smell
    • Black color
    • No white-colored (engine coolant cross contamination)
  3. If there are signs of the above conditions, remove the automatic transmission assembly and disassemble to inspect and or replace as necessary. Be sure to flush the oil cooler lines and the cooler assembly as necessary.
  4. "White-colored/milkshake ATF" is caused by mixing of water/engine coolant. Therefore, inspect the oil cooler system for signs of damage and repair as necessary. Refer to Transmission Fluid Cooler Flushing and Flow Test .