B3873

DTC B3873

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B3873 01
- Front Washer Relay Circuit Short to Battery

DTC B3873 02
- Front Washer Relay Circuit Short to Ground

DTC B3873 04
- Front Washer Relay Circuit Open Circuit

Diagnostic Fault Information






Circuit/System Description

The body control module (BCM) controls the windshield washer fluid pump based on an input from the windshield wiper/washer switch. The BCM monitors the washer switch through the windshield washer switch signal circuit. When the wash switch is closed, ground is supplied to the windshield washer switch signal circuit. When this is the case, the BCM will command the windshield washer fluid pump and the low speed wipers on.

Conditions for Running the DTC

* Ignition ON.

* The system voltage is between 9-16 V.

Conditions for Setting the DTC

* A short to ground or an open/high resistance is detected in the windshield washer relay control circuit.

* A short to voltage is detected in the windshield washer relay control circuit.

Action Taken When the DTC Sets

Washer operation is suspended.

Conditions for Clearing the DTC

A current DTC clears when the diagnostic runs and passes.

Reference Information

Schematic Reference

Wiper/Washer Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

Description and Operation

Wiper/Washer System Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the X50A underhood fuse block.

2. Connect a test lamp between the control circuit terminal G9 and ground, ignition ON.

3. Verify the test lamp turns ON and OFF when commanding the Windshield Washer Relay ON and OFF with a scan tool.

• If the test lamp is always OFF

1. Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.

2. Test for infinite resistance between the control circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If the test lamp is always ON

1. Ignition OFF, disconnect the harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K9 body control module.

• If the test lamp turns ON and OFF

4. Replace the X50A underhood fuse block.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Front Compartment Fuse Block Replacement Service and Repair

* Control Module References Control Module References for BCM replacement, programming and setup