Gear Lockout: Description and Operation

With the ignition switch in ON (II) or START (III), battery voltage is supplied through fuse 13 to the reverse lockout relay. The Vehicle Speed Sensor (VSS) provides a vehicle speed signal to the Engine Control Module (ECM). When the speed is above 12 mph (20 km/h), the ECM grounds the reverse lockout relay causing it to close. This energizes the reverse lockout solenoid which keeps you from shifting into reverse. When the vehicle speed is below 9 mph (15 km/h), the relay opens and you can then shift into reverse.