GM Service Manual Online
For 1990-2009 cars only

Soft Shift

Checks

Cause

Line Pressure

Too low

Pressure Control Solenoid Valve (320)

    â€¢ Stuck On
    â€¢ A broken clip is causing leakage
    â€¢ Pinched wire to ground

VCM/PCM

Failed

Accumulator Piston

    â€¢ Leaking
    â€¢ Stuck

Accumulator Spring

Incorrect

Calibration PROM

Incorrect

Check the VCM/PCM for current DTCs