Ignition Switch System

The ignition switch controls the ignition states, including OFF, ACC, ON and START. This allows some systems to be activated without starting the vehicle.

OFF 

The BCM supplies voltage to the ignition switch. When the ignition switch is in the OFF position, the switch is open, preventing voltage from being distributed to the various electrical systems.

ACC 

When the ignition switch is in the ACC position, the switch routes voltage through the ACC-designated circuit to the BCM. The BCM provides voltage to various vehicle electrical components. This allows functionality of specific electrical systems without placing additional current drain on the battery from the powertrain electrical system when the vehicle is not running.

ON 

When the ignition switch is in the ON position, the ignition switch routes voltage through the ACC-designated and ON designated circuits. It provides voltage to the BCM to indicate the ignition status but it is not a power supply to the BCM.

START 

When the ignition switch is in the START position, the switch routes voltage through the START-designated circuit to indicate a START to the BCM. The START-designated circuit is only used for vehicle starting.

Ignition Key Inhibit 

The ignition key cylinder inhibit feature prevents the ignition lock cylinder from being rotated to the OFF position when the vehicle is not in PARK.

Battery voltage is supplied to the inhibit solenoid within the ignition switch. A switch within the selector lever assembly controls the ground side of the inhibit solenoid. When the selector lever is in PARK, the switch is open, allowing the ignition lock cylinder to rotate through all its positions. When the selector lever is moved out of PARK, the switch closes and the ignition key inhibit solenoid energizes to prevent the ignition lock cylinder and ignition switch from rotating to the OFF position. This also prevents the key from being removed from the ignition lock cylinder.