Principles of Operation

Principles of Operation

Steering Column Switches
The steering column switches include the ignition switch and the multi-function switch (high beam/low beam, flash-to-pass, turn signal and windshield wiper).

Ignition Switch
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 various components and systems. The ignition switch also contains a key-in ignition system that allows the smart junction box (SJB) to detect when the key has been inserted into the ignition switch. The available ignition switch positions are:
^ OFF
^ CC
^ RUN
^ START

Multi-Function Switch
The multi-function switch controls the various components (high beam headlamps, flash-to-pass, turn signal and windshield wiper) by grounding certain SJB circuits and wiper motor circuits. When the SJB detects the specific ground, it sends a voltage to the appropriate component to activate it. The SJB controls the high beam headlamps, the flash-to-pass and the turn signals. The high beam headlamp and the turn signal portion are normally open switches that close when activated. The flash-to-pass switch is a momentary contact switch that grounds the SJB high beam headlamp circuit. The windshield wipe and wash functions are controlled directly by the multi-function switch, wiper and washer motor.

For multi-function switch concerns, refer to one of the following information:
^ For exterior lighting, refer to Lighting and Horns.
^ For wipers and washers, refer to Wiper and Washer Systems.