Ignition Switch: Description and Operation

IGNITION SWITCH AND KEY LOCK CYLINDER
The ignition switch is located on the steering column. The Key-In-Switch is located in the ignition switch module.

On vehicles equipped with an automatic transmission, a cable connects an interlock device within the steering column assembly to the transmission floor shift lever. This interlock device is used to lock the transmission shifter in the PARK position when the key is in the LOCKED or ACCESSORY position. The interlock device is not serviceable. If repair is necessary, the steering column assembly must be replaced.

On vehicles equipped with a manual transmission, a lever is located on the steering column behind the ignition key lock cylinder. The lever must be operated to allow rotation of the ignition key lock cylinder. The lever mechanism is not serviced separately If repair is necessary, the steering column assembly must be replaced.

CIRCUIT OPERATION
Circuit A1 from fuse 3 in the Power Distribution Center (PDC) and circuit A2 from PDC fuse 2 supply battery voltage to the ignition switch. Depending upon position, the ignition switch powers circuits A21, A22, A31, or A41.

Start Position
In the START position, the ignition switch connects circuit A2 to circuit A41. Circuit A41 connects to circuit T141 which powers the coil side of the starter motor relay

Additionally in the START position, the case grounded ignition switch provides ground for the brake warning lamp switch.

Start Or Run Position
In the START or RUN position, the ignition switch connects circuit A1 to circuit A21. Circuit A21 feeds fuses 9, 10, and 11 in the fuse block.

Run (Only) Position
When the ignition switch is in the RUN position, it connects circuit A2 to circuit A22. Circuit A22 feeds fuses 5, 6, 7, and 8 in the fuse block.

Accessory Or Run Positions
In the ACCESSORY or RUN positions, the ignition switch connects circuit A1 to circuit A31. Circuit A31 feeds fuses 13, 14 and 15 in the fuse block and the accessory relay.