Vauxhall Workshop Service and Repair Manuals

DTC B371A

Diagnostic Instructions

DTC Descriptor

Circuit/System Description

B+ voltage and ground are supplied to the windscreen wiper motor. Whenever the ignition is ON, or in accessory positions, the body control module (BCM), sends the wiper/washer switch status through the LIN communication bus. If a fault occurs at any time in the windscreen wiper motor, the BCM will set this DTC.

Conditions for Running the DTC

The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.

Conditions for Setting the DTC

The BCM receives an invalid signal from the windscreen wiper motor.

Action Taken When the DTC Sets

The module refuses all additional inputs.

Conditions for Clearing the DTC

A current DTC clears when the diagnostic runs and passes.

Diagnostic Aids

Diagnose any communication DTCs (U-Codes) before attempting any diagnosis.

Reference Information

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

Circuit/System Testing

Left Hand Drive

1. Ignition OFF, Retained Accessory Power OFF, disconnect the harness connector at the M75 Windscreen Wiper Motor.
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 4-12 V between the communication signal circuit terminal 4 and ground.

⇒	If not the specified range, test the signal circuit for an open/high resistance and a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.

5. If all circuits test normal, replace the M75 Windscreen Wiper Motor.

Right Hand Drive

1. Ignition OFF, Retained Accessory Power OFF, disconnect the harness connector at the M75 Windscreen Wiper Motor.
2. Test for less than 5 Ω between the ground circuit terminal 3 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 4 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 4-12 V between the communication signal circuit terminal 1 and ground.

⇒	If not the specified range, test the signal circuit for an open/high resistance and a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.

5. If all circuits test normal, replace the M75 Windscreen Wiper Motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.