Theory Of Operation

Windshield Wipers:  The Front Wiper/Washer Switch is located on the Left Multifunction Switch and is hard-wired to the Body Control Module (BCM). Voltage is provided to the Front Wiper Motor from a fuse in the Front Power Distribution Center (PDC) Assembly, through the Fused B(+) circuit. A ground path for the Front Wiper Motor is provided through the wiring harness to the body of the vehicle. The Light Rain Sensor Module (LRSM) is located on the windshield and is hard-wired to the Body Control Module (BCM). Voltage is provided to the LRSM from a fuse in the BCM, through the Fused Ignition Switch Output (Run) circuit. A ground path for the LRSM is provided through the wiring harness to the body of the vehicle.

When the BCM receives a signal to activate the Front Wipers from the Front Wiper Switch or the LRSM, the BCM sends a LIN Bus output through the LIN Bus 2 circuit to Front Wiper Motor. The speed of the Front Wiper Motor is determined by the LIN Bus output sent by the BCM.

Windshield Washers:  When the BCM receives a Windshield Washer request from the Left Multifunction Switch, the BCM activates the Front Washer Pump Relay, integral to the BCM, which provides a voltage output to the Windshield Washer Pump, through the Front Washer Pump Motor Control circuit. A ground path for the Windshield Washer Pump is provided through the wiring harness to the body of the vehicle.

Headlamp Washers (if equipped):  When the ignition is on, the BCM provides fused voltage to the Headlamp Washer Relay, located in the Front PDC Assembly, through the Ignition Run/Start Output circuit. When the BCM receives a Headlamp Washer request from the Left Multifunction Switch, the BCM sends a ground output to the Headlamp Washer Relay, which activates the relay. When the Headlamp Washer Relay is activated, the relay sends voltage to the Headlamp Washer Motor. A ground path for the Headlamp Washer Pump is provided through the wiring harness to the body of the vehicle.