GM Service Manual Online
For 1990-2009 cars only

Checks

Cause

Line Pressure

Too low

Pressure Control Solenoid Valve (320)

    • Stuck On
    • A broken clip is causing leakage.
    • Pinched wire to ground

PCM

Failed

Accumulator Piston

    • Leaking
    • Stuck

Accumulator Spring

Incorrect

Calibration PROM

Incorrect

Check the PCM for current DTCs.

Shift Solenoids

Leaking

4th Accumulator Piston Pin Retainer Ring

Missing