GM Service Manual Online
For 1990-2009 cars only

Condition

Action

DEFINITION: Slips in reverse or no reverse

Fluid level low and/or burnt

    • Perform Transmission Fluid Check .
    • If low inspect for fluid leak, repair as necessary.
    • Inspect transmission oil cooler system for restricted or kinked lines.
    • Flush system. Refer to Transmission Fluid Cooler Flushing and Flow Test .

Fluid is contaminated with water or engine coolant

If contaminated with engine coolant replace transmission.

Unit filled with wrong type of fluid

Drain fluid and fill with proper type of fluid.

Shift cable or neutral park switch out of adjustment

    • Inspect neutral park switch alignment, adjust to correct position.
    • Inspect shift cable adjustment, adjust for proper operation.

Line pressure control solenoid valve assembly (SLT) (312)

    • Perform electrical function checks on the line pressure control solenoid valve assembly circuit.
    • Perform electrical function check on the line pressure control solenoid valve assembly (312).
    • Replace valve body assembly (39) if line pressure control solenoid valve assembly (312) is faulty.

Torque converter (1)

Replace torque converter (1).

Valve body (39)

Replace valve body (39).

Internal transmission part failure

    • Disassemble the transmission and inspect the following:
       - Clutch assemblies, O-rings cut or damaged, clutch disc failure
       - Fluid pump wore, scored or broken gears
       - Broken shafts or gears
    • Replace transmission if any internal parts are faulty.