Theory Of Operation

FRONT WIPERS: 

The Front Wiper Switch is part of the Right Multifunction Switch, which is integral to the Steering Column Control Module (SCCM). The SCCM sends Front Wiper Switch commands through the CAN C Bus, to the Body Control Module (BCM).

When the BCM receives a CAN Bus message to activate the Front Wiper Motor at low speed, the BCM provides a voltage output through the Wiper On/Off Relay Control circuit, to energize the coil side of the Wiper On/Off Relay (integral to the Power Distribution Center (PDC) Assembly). When the Wiper On/Off Relay is active, a voltage output is sent through the Wiper High/Low Relay (integral to the PDC Assembly) to the Front Wiper Motor, through the Wiper Low Speed Control Output circuit, which activates the Front Wiper Motor at low speed.

When the BCM receives a CAN Bus message to activate the Front Wiper Motor at high speed, the BCM provides a ground output through the Wiper High/Low Relay Control circuit, to energize the coil side of the Wiper High/Low Relay. When the Wiper High/Low Relay is active, a voltage output is sent from the Wiper High/Low Relay to the Front Wiper Motor, through the Wiper High Speed Control Output circuit, which activates the Front Wiper Motor at high speed.

A ground path for the Front Wiper Motor is provided through the wiring harness to the body of the vehicle.

REAR WIPER: 

The Rear Wiper Switch is part of the Right Multifunction Switch, which is integral to the Steering Column Control Module (SCCM). The SCCM sends Rear Wiper Switch commands through the CAN C Bus to the Body Control Module (BCM).

When the BCM receives a CAN Bus message to activate the Rear Wiper Motor, the BCM provides a voltage output through the Rear Wiper Relay Control circuit, to energize the coil side of the Rear Wiper Relay (integral to the PDC Assembly). When the Rear Wiper Relay is active, a voltage output is sent from the Rear Wiper Relay to the Rear Wiper Motor, through the Rear Wiper Control circuit, which activates the Rear Wiper Motor.

A ground path for the Rear Wiper Motor is provided through the wiring harness to the body of the vehicle.

WIPER PARK SWITCH: 

The Body Control Module (BCM) provides a battery reference voltage on the Front and Rear Wiper Park Switch Sense circuits, through internal pull-up resistors, to the Front and Rear Wiper Motors. The Wiper Park Switches are integral to the Front and Rear Wiper Motors and switch the Front or Rear Wiper Park Switch Sense circuits from open to ground as the Front or Rear Wiper Motor rotates.

WASHER PUMP MOTOR: 

The Washer Pump Motor is a reversible motor that is used for the Front and Rear Washers. The Front and Rear Washer Switches are part of the Right Multifunction Switch, which is integral to the Steering Column Control Module (SCCM). The SCCM sends Front and Rear Washer Switch commands through the CAN C Bus to the Body Control Module (BCM).

When the BCM receives a CAN C Bus message to activate the Front Washers, the BCM provides a voltage signal to the Washer Pump Motor, through the Front Washer Pump Motor Control circuit, and a ground path through the Rear Washer Pump Motor Control circuit.

When the BCM receives a CAN C Bus message to activate the Rear Washer, the BCM provides a voltage signal to the Washer Pump Motor, through the Rear Washer Pump Motor Control circuit, and a ground path through the Front Washer Pump Motor Control circuit.