Diagnostic Instructions
DTC Descriptor
DTC B3922 Front Wiper Function Select Circuit
Circuit Description
The body control module (BCM) monitors the windshield wiper switch low signal
circuit. When the wiper switch is place in the low position, battery voltage is applied
through the switch contacts, a series of resistors, and the wiper switch low signal
circuit to the BCM. The BCM then applies battery positive voltage to the wiper relay
control circuit which energises the wiper relay. This applies battery voltage from
the WPR Fuse through the switch side of the relay to the windshield wiper motor.
Conditions for Running the DTC
| • | The ignition voltage is between 9-16 volts. |
Conditions for Setting the DTC
The BCM detects a short to ground or a short to battery voltage on the windshield
wiper switch low signal circuit.
Action Taken When the DTC Sets
| • | The BCM will not activate the low speed output. |
| • | The windshield wipers will only operate in the high speed mode. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The current DTC will become history when the request for the output is
removed. |
| • | The history DTC will clear after 50 fault-free ignition cycles. |
Reference Information
Schematic Reference
Wiper/Washer Schematics
.
Connector End View Reference
Component Connector End Views
.
Electrical Information Reference
Scan Tool Reference
Control Module References
Circuit/System Testing
- Disconnect the S247 Wiper switch connector and test for serviceability.
If the switch is not serviceable, replace the switch.
- Using a DMM test the Wiper switch; high, wash, return and mux circuits
for resistance.
| ⇒ | If greater than 5 ohms, repair or replace the effected circuit(s). |
| ⇒ | If less than 5 ohms, replace the BCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
