B3922

DTC B3922

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B3922 00
- Front Wiper Function Select Circuit




Diagnostic Fault Information






Circuit/System Description

The Body Control Module (BCM) monitors the windshield wiper/washer switch low signal circuit. When the wiper switch is placed 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 voltage through the wiper relay control circuit to energize the WIPER LO relay. When energized, battery voltage from the FRT WPR fuse is applied through the switch side of the WIPER LO relay then through the switch side of the WIPER HIGH relay to the windshield wiper motor.


Conditions for Running the DTC

Battery voltage is between 9 and 16 Volts.


The low speed BCM output is actively being requested.


Conditions for Setting the DTC

The BCM detects a short to ground or open high resistance on the BCM Fuse F9 B+ circuit.


The BCM detects a short to ground on the windshield wiper switch low speed signal circuit with wiper switch in OFF position and ignition in the OFF position .


Action Taken When the DTC Sets

* The BCM will not activate the low speed output.
* The windshield wipers will only operate in the delay and high speed modes.



Conditions for Clearing the DTC

* The DTC will clear the current status when the condition for setting the fault is corrected.
* A history DTC will clear after 100 consecutive ignition cycles without a fault present.



Reference Information
Schematic Reference

Wiper/Washer Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Wiper/Washer System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Ignition ON, observe the scan tool Windshield Wiper Switch parameter while rotating the wiper switch. The reading should change between Off, Intermittent, Low and High.


Circuit/System Testing

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Verify that a test lamp illuminates between the B+ circuit terminal 3 and ground

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

3. Connect the X3 harness connector at the BCM, disconnect the harness connector at the windshield wiper/washer switch.
4. Ignition ON, verify the scan tool Windshield Wiper Switch parameter is Off.

• If not the specified value, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the windshield wiper/washer switch.



Component Testing

1. Ignition OFF, disconnect the harness connector at the windshield wiper/washer switch.
2. With the wiper switch in the HIGH position, test for less than 2 ohms between the low reference terminal 8 and the signal terminal 4.

• If greater than the specified range, replace the windshield wiper/washer switch.


Important: If the switch tests open in any switch position other than Off, test the signal circuits for a short to voltage before replacing the switch.


3. While cycling the wiper switch through each delay and speed position, test for the specified resistance between the low reference terminal 8 and the signal terminal 7.






If any switch position is not within the specified range, replace the windshield wiper/washer switch.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming
* Windshield Wiper and Washer Switch Replacement (Service and Repair)