Operation

OPERATION

The multi-function switch operates as follows:

- Front Washer Control - The control knob on the end of the multi-function switch control stalk is depressed towards the steering column to momentarily activate the washer pump in the front washer mode. The washer pump will continue to operate in the front washer mode until the control knob is released. The multi-function switch provides an output by sending electronic front washer switch status messages to the Front Control Module (FCM) over the Controller Area Network (CAN) data bus. The FCM responds by energizing or de-energizing the washer pump in the front washer mode.
- Front Wiper Control - The control knob on the end of the multi-function switch control stalk is rotated to one of the continuous front wiper detents, to one of six intermittent ( or auto wipe sensitivity positions if so equipped) wiper detents, or to the Off position to select the front wiper mode. The multi-function switch provides an output by sending electronic front wiper switch status messages to the FCM over the CAN data bus. The FCM responds by energizing or de-energizing the wiper on/off and high/low relays in the Power Distribution Center (PDC) for front wiper system control.
- Headlamp Beam Selection - The control stalk of the multi-function switch is pushed toward the instrument panel for a latching high beam selection. Pulling the stalk rearward toward the steering wheel for a latching low beam selection. Each time the control stalk is actuated to the momentary position with the headlamps turned off, the headlamp high beams will be illuminated for as long as the control stalk is held in this position. The multi-function switch provides an output to the FCM over the CAN data bus. The FCM energizes or de-energizes the selected low or high beam circuits.
- Turn Signal Control - The control stalk of the multi-function switch is moved upward to activate the right turn signal circuitry, and, downward to activate the left turn signal circuitry. The turn signal switch has a detent position in each direction that provides turn signals with automatic cancellation, and an intermediate, momentary position in each direction that provides turn signals only until the control stalk is released. When the control stalk is moved to a turn signal switch detent position, the cancel actuator extends toward the center of the steering column. A turn signal cancel cam that is integral to the clockspring rotates with the steering wheel and the cam lobes contact the cancel actuator when it is extended from the multi-function switch. When the steering wheel is rotated during a turning maneuver, one of the two turn signal cancel cam lobes will contact the turn signal cancel actuator. The cancel actuator latches against the cancel cam rotation in the direction opposite that which is signaled. If the left turn signal detent is selected, the lobes of the cancel cam will ratchet past the cancel actuator when the steering wheel is rotated to the left, but will unlatch the cancel actuator as the steering wheel rotates to the right and returns to center, which will cancel the turn signal event and release the control stalk from the detent so it returns to the neutral Off position. When a turn signal is activated, the multi-function switch provides an output to the FCM over the CAN data bus. In addition, the message is sent to the CCN via the CAN bus to activate the proper signal within the EMIC. The FCM energizes and flashes or de-energizes the selected left or right turn signal circuits.

The multi-function switch can be diagnosed using a diagnostic scan tool and the appropriate diagnostic information.

The multi-function switch cannot be adjusted or repaired. If any function of the switch is faulty, or if the switch is damaged, the entire switch must be replaced as a unit. Removal and Replacement