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 00: Front Washer Relay 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 | 2 | 1 | B3873 00 | --
Windshield Washer Fluid Pump Ground | -- | 1 | -- | --
1. Washer Inoperative 2. Washers Always ON

### Circuit/System Description

The body control module (BCM) controls the washer motor 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 seen, the BCM will command the windshield washer fluid pump and the low speed wipers on.

### Conditions for Running the DTC

A washer request is present.

### Conditions for Setting the DTC

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 will clear when the condition for setting the fault is no longer seen.

• | A history DTC will clear after 50 consecutive ignition cycles without a fault present.

### 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 Scan Tool Information

### Circuit/System Verification

Operate the washers using the WASH switch. Verify the washer pump activates.

### Circuit/System Testing

1. Ignition OFF, disconnect the X3 harness connector at the underhood fuse block.
2. Connect a test lamp between the control circuit terminal 25 and B+.
3. Ignition ON, command the washers ON and OFF using the WASH switch. 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 ground. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. If all circuits test normal, replace the underhood fuse block.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure

• | Underhood Electrical Center or Junction Block Replacement

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