Diesel Data: Automotive Repair

Principles of Operation




Steering Column Switches

Principles of Operation

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

Ignition Switch

The ignition switch is controlled by the ignition lock cylinder with a key. When the ignition 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 specific components. The ignition switch and cylinder are contained in the steering column lock module and can be serviced separately.

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 (flash-to-pass, high beam, turn signal and windshield wiper/washer) controls the various components electrically. The multifunction switch is hard-wired to the SJB and controls a ground signal for the high beam, flash-to-pass and turn signal functions. The multifunction switch is also hard-wired to the smart wiper module and controls a ground signal for the various wiper and washer functions.

For headlamp and turn signal concerns, refer to Exterior Lighting Testing and Inspection and Testing and Inspection. For wiper and washer concerns, refer to Wipers and Washers Testing and Inspection.