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.

### Circuit/System Description

The rear wiper is controlled based on an input from the rear wiper/washer switch. When the wiper portion of the rear wiper/washer switch is closed, a ground signal is provided to the rear window wiper motor indicating rear wiper operation is request. The rear wiper motor receives B+ voltage from the I/P fuse block and accessory voltage from the BCM. The rear wiper motor also monitors the state of the liftgate ajar indicator and will suspend rear wiper operating when the liftgate is open.

### 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

1. Ignition ON, liftgate closed, verify the liftgate ajar indicator is not illuminated.

⇒ | If the liftgate ajar indicator is illuminated, refer to Liftgate Ajar Indicator Malfunction

2. Command the rear wiper ON using the rear wiper/washer switch. The rear wiper should activate.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the rear wiper/washer switch.
2. Test for less than 5 ohms of resistance between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Reconnect the harness connector at the rear wiper/washer switch. Disconnect the harness connector at the rear window wiper motor.
4. Test for less than 20 ohms of resistance between the ground circuit terminal A and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

5. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal C and ground.

⇒ | If the test lamp does not illuminate, test he B+ circuit for an open/high resistance. If the RR WPR fuse is open, test the B+ circuit for a short to ground. If the circuit tests normal, test or replace the rear window wiper motor.

6. Verify a test lamp illuminates between the ignition circuit terminal D and ground.

⇒ | If the test lamp does not illuminate, test he ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Ignition OFF, liftgate closed, test for less than 20 ohms of resistance between the signal circuit terminal F and ground.

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, refer to Liftgate Ajar Indicator Malfunction.

8. Rear wiper switch closed, test for less than 10 ohms of resistance between the signal circuit terminal B and ground.

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, test or replace the rear wiper/washer switch.

9. If all circuits test normal, test or replace the rear window wiper motor.

### Component Testing

#### Rear Wiper/Washer Switch

1. With the rear wiper switch in the open position, test for infinite resistance between the ground terminal 1 and the signal terminal 2.

⇒ | If not the specified value, replace the rear wiper/washer switch.

2. With the rear wiper switch in the closed position, test for less than 2 ohms of resistance between the ground terminal 1 and the signal terminal 2.

⇒ | If not within the specified range, replace the rear wiper/washer switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure

Liftgate Wiper Motor Replacement