Principles of Operation

Steering Column Switches

Principles of Operation

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

Steering Column Switches

The steering column switches include the ignition switch and the multifunction 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 SJB (Smart Junction Box) to detect when the key has been inserted into the ignition switch. The available ignition switch positions are:

- OFF

- ACC

- RUN

- START

Key Removal Inhibit Solenoid

The key removal inhibit solenoid (also known as the key release interlock actuator) is an electronically controlled solenoid that prevents the ignition lock cylinder from being turned to the OFF position unless the selector lever is in the PARK position. The key removal inhibit solenoid is part of the ignition switch.

Multifunction Switch

The multifunction switch controls the various components (high beam headlamps, flash-to-pass, turn signal and windshield wiper) by grounding certain SJB (Smart Junction Box) circuits and wiper motor circuits. When the SJB (Smart Junction Box) detects the specific ground, it sends a voltage to the appropriate component to activate it. The SJB (Smart Junction Box) 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 (Smart Junction Box) high beam headlamp circuit. The windshield wipe and wash functions are controlled directly by the multifunction switch, wiper and washer motor.

For multifunction switch concerns, refer to one of the following system:

- For exterior lighting, refer to Lighting and Horns.

- For wipers and washers, refer to Wiper and Washer Systems.