GM Service Manual Online
For 1990-2009 cars only

The reverse inhibit solenoid is a safety feature which prevents an inadvertent shift into reverse at speeds above 5 km/h (3 mph). The system consist of the following components:

    • The powertrain control module (PCM).
    • The reverse inhibit solenoid.

With the ignition ON, battery voltage is supplied directly to the reverse inhibit solenoid. At forward speeds above 5 km/h (3 mph) the PCM opens the control circuit of the reverse inhibit solenoid. This de-energizes the solenoid and mechanically blocks the shift lever from going into the REVERSE position.