B+ voltage is supplied to the windshield outside moisture sensor. Whenever the ignition is ON, or in accessory positions, the body control module (BCM), sends the turn signal/multifunction switch status by using a pulse width modulated (PWM) signal. When a wipe cycle is needed, the windshield outside moisture sensor sends a PWM voltage signal to the BCM, requesting the wiper operation. The BCM commands the windshield wiper motor wipe cycles. If at anytime a fault occurs between the windshield outside moisture sensor and BCM, the BCM will use the inputs from the turn signal/multifunction switch in the delay positions to operate the windshield wiper motor at continuous variable delay intervals.

Schematic Reference

Wiper/Washer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Wiper/Washer System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, S78 Turn Signal/Multifunction Switch in the low position. The windshield wipers should operate at low speed.

If the windshield wipers do not operate, refer to Windshield Wiper System Malfunction.

Rain Sensor Malfunction

1. Ignition OFF, disconnect the harness connector at the B11  Windshield Outside Moisture Sensor.
2. Test for less than 5 Ω between the ground circuit terminal 2 and ground.

⇒	If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between B+ voltage circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the B+ voltage circuit for a short to ground or an open/high resistance.

4. Ignition ON, test for 4-10 V between the signal circuit terminal 3 and ground.

⇒	If less than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM).

5. If all circuits test normal, replace the B117 Windshield Outside Moisture Sensor.

Rain Sensor Indicator Malfunction

1. Ignition ON, command the Driver Information Center Segments test ON and OFF with the scan tool, verify that the rain sensor display reacts to ON and OFF positions.

⇒	If the rain sensor display stays always ON or always OFF, replace the P16 Instrument Cluster.

2. If the rain sensor display changes between ON and OFF, replace the K9 Body Control Module (BCM).

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.