Switch, MULTIFUNCTION, Right: Operation
The right (wiper) multifunction 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 multifunction 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 multifunction switch requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
Following are descriptions of how the right multifunction switch is operated to control the functions and features it provides:
- Wiper Control - The right multifunction switch control stalk (1) is moved downward to the speed sensitive intermittent wiper detent or one of the two continuous wiper detents. With the stalk in the intermittent wiper position, the control knob (3) is rotated to select one of the four speed sensitive delay intervals. The right multifunction switch control stalk is raised upward to select the momentary wiper Mist position. The 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 multifunction switch and electronic vehicle speed message inputs from the Antilock Brake Module (ABM) and provides a hard-wired output to control the relays that energize or de-energize the wiper motor as appropriate.
- Washer Control - The right multifunction switch control stalk is pulled rearward towards the steering wheel to a momentary Wash position to activate the washer pump/motor in the Wash mode. The washer pump/motor will continue to operate for as long as the control stalk is held in this position. If the control stalk is held in the Wash position for more than about half a second, the wiper motor will begin to operate and will continue to operate for about three complete strokes after the control stalk is released. There will also be one additional wiper stroke about six seconds after the control stalk is released. The BCM reads the resistor multiplexed input from the right multifunction switch and provides hard-wired outputs to control the washer pump/motor and the wiper motor as appropriate.
- In addition, a small TRIP push button (2) at the very end of the right multifunction switch control knob provides a signal to the Instrument Panel Cluster (IPC) that will reset the currently displayed trip odometer A or B value to zero.