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.

### 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. 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 washer 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.

### 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

Ignition ON. Operate the washers by using the S78 Turn Signal/Multifunction Switch. Verify the G24 Windshield Washer Fluid Pump activates.

⇒ | If the G24 Windshield Washer Fluid Pump does not activate, refer to washer pump circuit malfunction.

⇒ | If the low speed wipers do not turn on, refer to Windshield Wiper System Malfunction.

### Circuit/System Testing

#### Multifunction Switch

1. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module (BCM).
2. Test for less than 5 Ω between the signal circuit terminal 25 and signal circuit terminal 7 while activating the washer function.

⇒ | If greater than the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the S80 Window Wiper/Washer Switch.

3. Ignition OFF, test for greater than 500 kΩ between the signal circuit terminal 25 and ground.

⇒ | If less than the specified value, test the signal circuit terminal 25 for a short to ground. If the circuit tests normal, replace the S80 Window Wiper/Washer Switch.

4. Ignition OFF, disconnect the X4 harness connector at the K9 body control module (BCM).
5. Ignition ON, install a 10 A fused jumper wire between the signal circuit terminal 14 and B+. Observe the G24 Windshield Washer Fluid Pump is operating.

⇒ | If the G24 Windshield Washer Fluid Pump does not activate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the X50A Fuse Block - Underhood Primary.

6. If all circuits test normal, test or replace the K9 Body Control Module (BCM).

#### Washer Pump

1. Ignition OFF, remove the F56 Fuse at the X50A Fuse Block - Underhood Primary.
2. Ignition ON, verify a test lamp does illuminate between the F56 Fuse input terminal and ground.

⇒ | If the test lamp does not illuminate, test the voltage circuit for a short to ground or an open/high resistance.

3. Ignition OFF, install the F56 Fuse and disconnect the harness connector at the G24 Windshield Washer Pump.
4. Ignition ON, verify a test lamp does illuminate between the voltage circuit terminal 1 and the ground circuit terminal 2 at the G24 Windshield Washer Pump harness connector while operating the washers.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance or a short to voltage.

⇒ | If the test lamp does not illuminate, test the voltage circuit for an open/high resistance or a short to ground.

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

### Component Testing

#### Multifunction Switch

1. Ignition OFF, disconnect the harness connector at the S80 Window Wiper/Washer Switch.
2. Test for less than 5 Ω between the S80 Window Wiper/Washer Switch terminal 2 and terminal 7 while activating the washers.

⇒ | If not the specified value, replace the S80 Window Wiper/Washer Switch.

#### Washer Pump

1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Fluid Pump.
2. Install a 10 A fused jumper wire between the control terminal 1 and 12 V. Install a jumper wire between the ground terminal 2 and ground.
3. Verify the G24 windshield washer fluid pump is activated.

⇒ | If the G24 Windshield Washer Fluid Pump does not activate , replace the G24 Windshield Washer Fluid Pump.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Windshield Washer Pump Replacement

• | Relay Replacement

• | Windshield Wiper and Washer Switch Replacement

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

• | Front Compartment Fuse Block Housing Replacement