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. For removal/installation of either the key lock cylinder or ignition switch, refer to Ignition Switch and Key Cylinder Service and Repair.

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. The shifter interlock cable can be adjusted or replaced.

CIRCUIT OPERATION
Circuit A1 from fuse 8 in the Power Distribution Center (PDC) powers four different circuits through the ignition switch. when the ignition switch is in the START or RUN position, it connects circuit A1 to circuit A21.

In the ACCESSORY or RUN position, the ignition switch connects to circuit A31. In the START position, the ignition switch connects circuit A1 to circuit A41. When the ignition switch is in the RUN position it connects circuit A1 to circuit A22.

Also in the START position, the case grounded ignition switch grounds circuit G9 from the brake warning switch.