Principles of Operation

Steering Column Switches

Principles of Operation


Ignition Switch

NOTE: The Smart Junction Box (SJB) is also identified as the Generic Electronic Module (GEM).

The ignition switch is controlled by the ignition lock cylinder with a key. When the ignition lock cylinder is turned using the key, a mechanical connection positions the ignition switch to the selected position and allows the ignition switch to send voltage to the SJB. The ignition switch also contains a key-in-ignition system that allows the instrument cluster to detect when the key has been inserted in the ignition switch. This information is used by the instrument cluster for the brake shift interlock system and for the chime warning system. For information on the chime warning system, refer to Instrument Panel, Gauges and Warning Indicators.

The available ignition switch positions are:

- OFF
- ACC
- RUN
- START


Multifunction Switch

The multifunction switches control various components electrically. The headlamp switch sends constant voltage to the headlamps when placed in the ON position, while the flash-to-pass is a momentary switch used to send voltage to the headlamp high beams only. The headlamp high beam/low beam switch sends voltage to the low or high beam headlamps while the headlamps are on. The turn signal switch of the multifunction switch operates the left and right turn signals. The windshield wiper switch function uses a ground signal to activate the various wiper modes and the wiper/washer.

For diagnosis and testing of the multifunction switch, refer to Lighting and Horns Lighting and Horns for headlamps and turn signal concerns, and Wiper and Washer Systems for wiper and washer concerns.