GM Service Manual Online
For 1990-2009 cars only

Check

Causes

DEFINITION: A large engine RPM increase is noted, with no vehicle forward speed increase, during the following conditions:

The engine is running.

The transmission is in Drive range.

The vehicle is stopped or moving slowly.

The vehicle brakes are not applied.

The throttle is opened 25 percent or greater.

Forward Clutch Assembly

    • Damaged or worn clutch plates
    • Damaged or cut piston
    • Damaged or stuck ball check valve

Forward Clutch Sprag

    • Damaged sprag
    • Worn or pitted inner race

Fluid Pump

    • Damaged vanes
    • Missing slide spring
    • Fluid pump screen assembly plugged or damaged
    • Fluid pump rotor guide omitted or misassembled
    • Fluid pump rotor cracked or broken
    • Porosity in fluid pump
    • Fluid pump surfaces not flat
    • Excessive fluid pump rotor clearance

Low Clutch Sprag

    • Damaged sprag
    • Worn or pitted inner race

Input and Reaction Carrier

Damaged or worn gears