Windshield Washer Motor: Description and Operation

FRONT WASHER MOTOR
The front washer switch is a direct input to the BCM. The BCM sends a PCI Bus message to the FCM informing it of a request to wash. The front washer motor is then powered through low side control inside the FCM. This circuit is electronically controlled and continuously monitored for malfunctions. In addition, the FCM electronically protects the washer motor from system voltages higher than 16 volts by automatically switching off the low side circuit. The low side circuit is connected to pin 45 in the FCM connector.

REAR WASHER MOTOR
The rear washer switch is a direct input to the BCM. The BCM sends a PCI Bus message to the FCM informing it of a request to wash. The rear washer motor is then powered through low side control inside the FCM. This circuit is electronically controlled and continuously monitored for malfunctions. In addition, the FCM electronically protects the washer motor from system voltages higher than 16 volts by automatically switching OFF the low side circuit. The low side circuit is connected to pin 46 in the FCM connector.