Right Multifunction Switch - Operation

OPERATION

The right (wiper) multi-function switch uses resistor multiplexing to control the many functions and features it provides using a minimal number of hard wired circuits. The switch receives clean grounds from the Body Control Module (BCM), then provides resistor multiplexed return outputs to the BCM to indicate the selected switch positions. The BCM then sends hard wired control outputs as well as electronic switch status messages over the Controller Area Network (CAN) data bus to other electronic modules in the vehicle.

Some of the hard wired inputs and outputs of the BCM and the right multi-function switch unit may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, the most reliable, efficient and accurate means to diagnose the BCM and the right multi-function switch requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

Following are descriptions of how the multi-function switch is operated to control the functions and features it provides:

- Front Wiper Control - The right multi-function switch control stalk is moved downward to one of the two continuous wiper detents or to the speed sensitive intermittent wiper detent. It is moved to the most upward detent position to select the front wiper OFF position, or upward past the OFF position to the momentary front wiper MIST position. The front wiper motor will continue to operate, one complete cycle at a time, for as long as the control stalk is held in the MIST position. The BCM reads the resistor multiplexed input from the right multi-function switch and provides a hard wired output to control the relays that energize or de-energize the front wiper motor as appropriate.
- Front Washer Control - The right multi-function switch control stalk is pulled rearward towards the steering wheel to a momentary FRONT WASH position to activate the washer pump/motor in the front washer mode. The washer pump/motor will continue to operate for as long as the control stalk is held in this position. The BCM reads the resistor multiplexed input from the right multi-function switch and provides hard wired outputs to control the washer pump/motor and the front wiper motor as appropriate.
- Rear Wiper Control - The rear wiper mode is selected when the right multi-function switch control knob is rotated to the fixed interval intermittent rear wipe detent position, or the OFF detent position. The BCM reads the resistor multiplexed input from the right multi-function switch and provides a hard wired output to control a relay that energizes or de-energizes the rear wiper motor as appropriate.
- Rear Washer Control - The right multi-function switch control stalk is pushed forward towards the instrument panel to a momentary REAR WASH position to activate the washer pump/motor in the rear washer mode. The washer pump/motor will continue to operate for as long as the control stalk is held in this position. The BCM reads the resistor multiplexed input from the right multi-function switch and provides hard wired outputs to control the washer pump/motor and the rear wiper motor as appropriate.