GM Service Manual Online
For 1990-2009 cars only

Reverse Lockout Control (Console Shift Only)

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

    • The engine control module (ECM)/powertrain control module (PCM)
    • The reverse lockout solenoid

With the ignition ON, battery voltage is supplied directly to reverse lockout solenoid. At forward speeds above 5 km/h (3 mph), the ECM/PCM commands the reverse lockout solenoid ON by grounding the control circuit of the solenoid. This energizes the solenoid and mechanically prevents the shift lever from being moved into the REVERSE position. At forward speeds below 5 km/h (3 mph), the ECM/PCM commands the reverse lockout solenoid OFF, de-energizing the solenoid, which allows the shift lever to move into the REVERSE position.