Heated Washer System Circuit Description

WARNING: This page is about a different car, the 2009 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

The washer solvent heater assembly provides a 5 volt reference voltage through the heated washer fluid switch signal to the heated washer fluid switch located on the Turn Signal/Multifunction Switch stalk. When the heated washer fluid switch is pressed, the signal circuit is closed to ground and the 5 volt supply is dropped across the resistor indicating the heated wash cycle request. The heater assembly sends a low side drive pulse width modulation (PWM) signal through the heated washer indicator signal circuit requesting the instrument panel cluster (IPC) to display the DIC HEATING WASH FLUID WASH WIPES PENDING message. After the above mentioned washer solvent temperature is reached, the heater assembly pulls the windshield washer switch signal circuit low requesting the BCM to activate the wash cycle.