Principles of Operation

Wipers and Washers

Principles of Operation

Windshield Wiper Operation

The multifunction switch supplies ground inputs to the wiper/washer module (located behind the Smart Junction Box (SJB) to determine the wiper speed, including low, high and intermittent. The wiper/washer module also receives feedback from the wiper motor to determine the park position. The wiper/washer module sends power to the wiper motor through the high and low circuits.

Wiper Activated Headlamps (If Equipped with Autolamp System)

The SJB sends a voltage signal to the wiper/washer module in order to monitor the status of the wipers. When the wipers are turned on, the wiper/washer module will pull the voltage down. Once the SJB detects a drop in voltage it will turn on the headlamps after 3 seconds. When the SJB detects the voltage raising, it will determine that the wipers have been turned off and the SJB will turn off the headlamps after 30 seconds.

Rain Sensitive Wipers (if equipped)

The rain sensor optically senses water on the windshield. An infrared beam, of specific intensity, lights a section of the windshield. The intensity of the reflected beam is measured and compared to the intensity of the transmitted beam. If there is water on the surface of the windshield, the beam distorts, reducing the intensity of the beam. If the beam is not reflected completely, it is interpreted as rain on the windshield and the windshield wipers are started.

The rain-sensing feature replaces the intermittent wiper feature. The rain sensor is located on the windshield to the right of the rear view mirror. In order to turn the rain sensitive wiper system on, the multifunction switch must be positioned to 1 of the 5 intermittent settings. The intermittent position closest to OFF is the least sensitive to moisture. The highest intermittent position is the most sensitive to moisture. When the rain sensitive wiper system is active and the rain sensor detects moisture on the windshield, the rain sensor will send a serial data message to the wiper/washer module to automatically activate the wipers.

Speed Sensitive Wipers

When the wiper control is set on any intermittent setting except INT 1, the speed dependant wipers will automatically adjust with the vehicle speed. Vehicle speed is supplied to the wiper/washer module from the PCM. The wiper/washer module is hardwired to the PCM. This feature decreases the time between wipes when the vehicle speed increases.