Volt

Windscreen Wiper System Malfunction

The Body Control Module (BCM) controls the wiper motor based on input from the windscreen wiper/washer switch. The BCM monitors the wiper/washer switch through two separate signal circuits and a ground circuit. The windscreen wiper switch high signal circuit is used to determine high speed wiper operation, the windscreen wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and the windscreen washer switch signal circuit is used to determine washer operation. The BCM controls the windscreen wiper motor low, high, and intermittent operations through a serial data Local Interconnect Network 1 (LIN) Bus control circuit.

Schematic Reference

Wiper/Washer Schematics

Steering Wheel Secondary/Configurable Control 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

1. Vehicle in Service Mode, S82 Windscreen Wiper/Washer Switch in the OFF position, verify the scan tool Windscreen Washer Switch parameter is INACTIVE.

⇒	If not the specified value, refer to Washer Malfunction .

2. S82 Windscreen Wiper/Washer Switch in the OFF position, verify the scan tool Windscreen Wiper Switch parameter is OFF.

⇒	If not the specified value, refer to Windscreen Wiper/Washer Switch Circuit Test.

3. S82 Windscreen Wiper/Washer Switch in the OFF position, verify the scan tool Windscreen Wiper High Speed Switch parameter is INACTIVE.

⇒	If not the specified value, refer to Windscreen Wiper/Washer Switch Circuit Test.

4. S82 Windscreen Wiper/Washer Switch in the LOW position, verify the scan tool Windscreen Wiper Switch parameter is LOW.

⇒	If not the specified value, refer to Windscreen Wiper/Washer Switch Circuit Test.

5. S82 Windscreen Wiper/Washer Switch in the HIGH position, verify the scan tool Windscreen Wiper High Speed Switch parameter is ACTIVE.

⇒	If not the specified value, refer to Windscreen Wiper/Washer Switch Circuit Test.

6. S82 Windscreen Wiper/Washer Switch in the INT position, cycling the delay adjustment switch from long delay to short delay, observe the scan tool Windscreen Wiper Switch parameter while cycling the delay adjustment switch from long delay to short delay. The parameter should cycle between Delay 1 through Delay 5 as each delay position is selected.

⇒	If not the specified value, refer to Windscreen Wiper/Washer Switch Circuit Test.

Windscreen Wiper/Washer Switch Circuit Test

1. Vehicle OFF, Retained Accessory Power OFF, disconnect the X1 harness connector at the S82 Windscreen Wiper/Washer Switch.
2. Verify a test lamp illuminates between terminal 2 and B+.

⇒	If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K9 BCM.

3. Vehicle in Service Mode, test for 9-11 V between the signal circuit terminal 3 and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.

4. Test for B+ between the signal circuit terminal 1 and ground.

⇒	If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

5. Disconnect the X3 harness connector at the K9 BCM.
6. Test for less than 1 V between terminal 20 and ground.

⇒	If greater than the specified value, test for a short to voltage.

7. Vehicle OFF, disconnect the harness connector at the S70R steering wheel control switch - right.
8. Vehicle in Service Mode, test for B+ between the voltage reference circuit terminal 1 and ground.

⇒	If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

9. If all circuits test normal, test or replace the S82 Windscreen Wiper/Washer Switch.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.