GM Service Manual Online
For 1990-2009 cars only

Reverse Lockout Control (Console Shift Only)

The reverse lockout system is a safety device that prevents an inadvertent shift from a forward or neutral gear into reverse. The system consists of the following components:

    • The reverse lockout relay
    • The reverse lockout solenoid
    • The dash integration module (DIM)

When the ignition switch is turned ON, battery voltage is supplied to the coil side feed circuit of the reverse lockout relay. The DIM supplies the ground for the control side circuit. When the DIM determines that the ignition is ON and the vehicle has been traveling at over 8 km (5 mph) for 15 seconds or longer, it grounds the control circuit of the reverse lockout relay. This energizes the relay and the switch side contacts close. Battery voltage flows through the switch side contacts of the relay to the reverse lockout solenoid. The reverse lockout solenoid is permanently grounded, this energizes the reverse lockout solenoid and mechanically prevents the shift lever from being moved into the REVERSE position.