Conventional 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 CJB 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 circuitry to various vehicle electrical components such as the IPC, the BCM and the CJB to power up specific vehicle systems. 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 switch routes voltage through the ACC-designated and ON-designated circuitry to power all the vehicle electrical systems.
START
When the ignition switch is in the START position, the switch routes voltage through the ON-designated circuitry and a separate circuit to the IPC and the PCM to start the vehicle. The circuit designated for the START mode is only used for vehicle starting.
Ignition Key Inhibit
On vehicles with an automatic transmission, 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 floor shifter controls the ground side of the inhibit solenoid. When the floor shifter is in PARK, the switch is open, allowing the ignition lock cylinder to rotate through all its positions. When the floor shifter 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.