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 Accessory Voltage | 2 | 1 | 1 | --
Windshield Washer Fluid Pump Control | 1 | 1 | 2 | --
Windshield Washer Fluid Pump Ground | -- | 1 | -- | --
1. Washer Inoperative 2. Washers Always ON

### Circuit/System Description

The windshield wiper washer switch controls the washer pump motor. When a wash cycle is requested ignition voltage is applied through the washer switch contacts to the washer pump control circuit activating the washer pump motor. The washer pump control circuit is monitored by the body control module (BCM) inorder to command low speed wipers on when a wash request is made. The washer pump motor has a constant ground at G102.

### Diagnostic Aids

• | If the wiper motor runs at high speed during the low speed modes replace the WIPER diode.

• | A short to ground in the following circuits will open the 10A WPR fuse located in the BCM fuse block:

- | Ignition 1 voltage

- | Windshield wiper switch high signal

- | Windshield washer switch signal

- | Windshield washer pump control

• | A short to ground in the following circuits will open the 25A WPR fuse located in the underhood fuse block:

- | Windshield wiper motor low speed control

- | Windshield wiper motor high speed control

### Reference Information

#### Schematic Reference

Wiper/Washer Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References

### Circuit/System Verification

1. Ignition ON, wiper switch in the OFF position, observe the scan tool Windshield Washer Switch parameter while cycling the WASH switch ON and OFF. The parameter should cycle between Active and Inactive.

⇒ | If the parameter does not cycle between the specified values, refer to Windshield Wiper/Washer Switch Circuit Malfunction.

2. Operate the washers using the WASH switch. Verify the washer pump activates and the low speed wipers turn on.

⇒ | If the washer pump does not activate, refer to Washer Pump Circuit Malfunction.

⇒ | If the low speed wipers do not turn on, refer to.

### Circuit/System Testing

#### Windshield Wiper/Washer Switch Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the Windshield Wiper/Washer switch.
2. Ignition ON, test for 12 volts between accessory voltage circuit terminal D and ground.

⇒ | If not the specified value, test the accessory voltage circuit terminal D for a short to ground. If the circuit tests normal, replace the BCM.

3. Ignition ON, verify the scan tool Windshield Washer Switch parameter is Inactive.

⇒ | If not the specified value, test the control circuit terminal B for a short to B+. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the control circuit terminal B and B+. Verify the scan tool Windshield Washer Switch parameter is Active.

⇒ | If not the specified value, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the Windshield Wiper/Washer switch.

#### Washer Pump Circuit Malfunction

1. Ignition OFF, Disconnect harness connector at Windshield Washer Fluid Pump.
2. Ignition ON, test for B+ at control circuit terminal A of Windshield Washer Fluid Pump connector while activating washers.

⇒ | If not the specified value, test the controll circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

3. Install a test light between control circuit terminal A and ground circuit terminal B at the windshield washer fluid pump connector
4. The test lamp should turn ON and OFF when the windshield washers are commanded ON and OFF.

⇒ | If not the specified value, test the ground circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

### Component Testing

#### Multifunction Switch

1. With the WASH switch in the open position, test for infinite resistance between the Accessory Voltage terminal D and the control terminal B.

⇒ | If not the specified value, replace the multifunction switch.

2. With the WASH switch in the closed position, test for less than 2 ohms between the Accessory Voltage terminal D and the control terminal B.

⇒ | If greater than the specified range, replace the multifunction switch.

#### Washer Pump

1. Ignition OFF, disconnect the harness connector at the washer pump.
2. Install a 10A fused jumper wire between the control terminal A and 12 volts. Install a jumper wire between the ground terminal B and ground.
3. Verify the washer pump is activated.

⇒ | If the washer pump does not activate , replace the washer pump.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Windshield Wiper and Washer Switch Replacement

• | Windshield Wiper Motor Replacement

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