GM Service Manual Online
For 1990-2009 cars only

Checks

Cause

Pump (203)

Cross channel air leak at body to cover, or cross channel air leak at body to case gasket

Pressure Regulator Valve (231)

Valve is stuck at a low torque signal, due to an undersized bore or to sediment.

Reverse Boost Valve (228)

Valve is stuck at a low torque signal, due to an undersized bore or to sediment.

Pump Valve Bores

Excessive valve clearance due to wear.

Spring (230)

The spring is broken.

Retainer Pin (211)

The pin is broken.

Valve Body (301)

    • Cross channel leaks
    • Cross valve land leaks

Gasket/Spacer Plate

The plate is damaged or missing.

Pressure Control Solenoid Valve (320)

    • The valve is stuck On.
    • A broken clip causes leakage.
    • A wire is pinched to ground.
    • A screen is missing.

PCM

Failed

Check the PCM for current DTCs.