GM Service Manual Online
For 1990-2009 cars only

Second and Third Gear Only

Checks

Cause

1-2 Shift Solenoid OFF Failure

    â€¢ Insufficient force of the solenoid
    â€¢ Foreign material is plugging the filter
    â€¢ The PCM is not grounding
    â€¢ Failure of the O-ring
    â€¢ No supply voltage to the 1-2 Shift Solenoid
    â€¢ Wires are not connected to the solenoid