Service Information

Orlando

DTC B3873

Diagnostic Instructions

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

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

•	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

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Windscreen Washer Switch Signal	2	1	1	--
Windscreen Washer Fluid Pump Control	1	1	2	--
Windscreen Washer Relay Control	B3873 02	B3873 04	B3873 01	-
Windscreen Washer Fluid Pump Ground	--	1	1	--
1. Washer Inoperative 2. Washer Always ON

The body control module (BCM) controls the windscreen washer fluid pump based on an input from the indicator/multifunction switch. The BCM monitors the washer switch through the windscreen washer switch signal circuit. When the wash switch is closed, ground is supplied to the windscreen washer switch signal circuit. When this is the case, the BCM will command the windscreen 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 windscreen washer relay control circuit.

•	A short to voltage is detected in the windscreen 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

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information.

Circuit/System Verification

Operate the washers by using the S82 Windscreen Wiper/Washer Switch. Verify that the G24 Windscreen Washer Pump activates.

Circuit/System Testing

Ignition OFF, disconnect the harness connector X2 at the X50A Fuse Block - Underhood.
Disconnect the harness connector X4 at the K9 Body Control Module.
Test for less than 5 Ω between the signal circuit terminal 60, harness connector X2 at the X50A Fuse Block - Underhood and the signal circuit terminal 14, harness connector X4 at the K9 Body Control Module.

⇒	If the resistance is not the specified value, test the signal circuit for an open circuit/high resistance or a short to voltage.

Test for 150-250 Ω between the relay control circuit terminal 60, harness connector X2 at the X50A Fuse Block - Underbonnet and ground.

⇒	If the resistance is not the specified value, test the relay control circuit for an open/high resistance, a short to voltage or a short to ground.

⇒	If all circuits test normal, test or replace the K9 Body Control Module.

If all circuits test normal, test or replace the X50A Fuse Block - Underhood.

Component Testing

Output Control Tests

Ignition ON, command the Windscreen Washer Relay Command ON and OFF with a scan tool. Observe that the KR11 Windscreen Washer Pump Relay clicks and the G24 Windscreen Washer Pump runs.

⇒	If the KR11 Windscreen Washer Pump Relay does not work, replace the X50A Fuse Block - Underhood.

⇒	If the KR11 Windscreen Washer Pump Relay works, but the G24 Windscreen Washer Pump does not run, test the control circuit.

⇒	If all circuits test normal, replace the G24 Windscreen Washer Pump.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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

•	Front Compartment Fuse Block Housing Replacement

•	Windscreen Washer Pump Replacement