GM Service Manual Online
For 1990-2009 cars only

Checks

Causes

Fluid Pump Assembly

    • Pressure regulator valve stuck
    • Pressure regulator valve spring
    • Line boost valve spring
    • Line boost valve or bushing stuck, damaged or incorrectly assembled
    • Pressure relief ball not seated or damaged
    • Pressure relief ball 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

Pressure Control Solenoid Assembly

    • Contaminated
    • O-Rings cut or damaged
    • Electrical connection

Inspect for active transmission DTCs

Transmission DTC default action active