For 1990-2009 cars

### 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 Descriptor

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

### Circuit/System Description

The body control module (BCM) controls the windshield washer fluid pump based on an input from the turn signal/multifunction 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 and 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

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Wiper/Washer System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for diagnostic tester information.

### Circuit/System Verification

Operate the washers by using the S80 Window Wiper/Washer Switch. Verify the G24 Windshield Washer Fluid Pump activates.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X2 at the X50A Fuse Block - Underhood Primary.
2. Disconnect the harness connector X4 at the K9 Body Control Module.
3. Test for less than 5 Ω between the signal circuit terminal 60, harness connector X2 at the X50A Fuse Block - Underhood Primary 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/high resistance.

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

### Component Testing

#### Output Control Tests

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

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

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

⇒ | If all circuits test normal, replace the G24 Windshield Washer Fluid 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

• | Windshield Washer Pump Replacement