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 - Primary
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 21 and ground.
3. Ignition ON, command the Windshield Washer Relay Command ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
4. Ignition OFF, connect the X2 harness at the X50A underhood fuse block and disconnect the harness connector at the G24 windshield washer pump.
5. Test for less than 5 ohms between the ground circuit terminal B and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
6. Connect a test lamp between control circuit terminal A and ground.
7. Ignition ON, command the Windshield Washer Relay Command On and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the X50A underhood fuse block.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the X50A underhood fuse block.
8. If all circuits test normal, test or replace the G24 windshield washer pump.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Windshield Washer Pump Replacement Windshield Washer Pump Replacement
* Control Module References Control Module References for BCM replacement, programming and setup