Operating Modes

WARNING: This page is about a different car, the 2016 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.

Following are paragraphs that briefly describe the operation of each of the rear wiper and washer system operating modes.

Continuous Wipe Mode - When the On position of the control sleeve on the control stalk of the multifunction switch is selected the SCCM microcontroller sends an electronic rear wiper switch on status message to the BCM over the CAN data bus. The BCM responds by energizing a HSD that provides an output to the rear wiper relay integral to the PCB within the PDC to direct battery current to the rear wiper motor, causing the wiper to cycle at a continuous speed.
When the Off position of the multifunction switch control sleeve is selected, the SCCM microcontroller sends an electronic rear wiper switch off status message to the BCM, then one of two events will occur. The event that occurs depends upon the position of the rear wiper blade on the liftgate glass at the moment that the control sleeve Off position is selected.

If the rear wiper blade is in the down position on the glass when the Off position is selected, the park switch that is integral to the rear wiper motor is an open circuit, which provides a hard wired park switch sense input to the BCM. The internal BCM circuitry pulls the park switch sense input to ground when the switch is open so that the microcontroller sees a ground when the wiper blade is parked. The BCM then de-energizes the rear wiper motor and the wiper motor ceases to operate. If the rear wiper blade is not in the down position on the liftgate glass at the moment the Off position is selected, the park switch is closed to fused ignition output and the BCM continues running the wiper motor at low speed until the rear wiper blade is in the down position on the liftgate glass and the park switch input to the BCM is again pulled to ground.
Intermittent Wipe Mode - When the Intermittent (INT ) position of the control sleeve on the control stalk of the multifunction switch is selected, the SCCM microcontroller sends an electronic rear wiper switch intermittent request message to the BCM over the CAN data bus. The BCM then provides the appropriate output to the rear wiper relay integral to the PCB within the PDC to direct battery current to the rear wiper motor at fixed delay intervals to enable the rear wiper motor intermittent wipe mode. The BCM uses a hard wired output from a park switch internal to the rear wiper motor as an additional logic input to monitor the position of the rear wiper blade on the glass and to control the delay interval between rear wiper sweeps.
Wash Mode - When the control sleeve of the multifunction switch is rotated clockwise or counterclockwise to one of the momentary rear Wash positions, the SCCM microcontroller sends an electronic rear washer switch request message to the BCM over the CAN data bus. The BCM then provides the appropriate output to the rear wiper relay integral to the PCB within the PDC to direct battery current to the rear wiper motor and directs battery current and ground to the washer pump/motor unit. These outputs will cause the washer pump motor and the rear wiper motor to operate continuously for as long as the switch is held closed up to approximately 10 seconds.
The washer pump is de-energized as soon as the control sleeve is released, but the rear wiper motor continues to operate for two to three continuous cycles before reverting to the previous mode of operation. The BCM uses a hard wired output from a park switch internal to the rear wiper motor as an additional logic input to monitor the position of the rear wiper blade on the glass and to control the number of continuous wiper sweeps following washer operation.