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 |
|---|---|---|---|---|
Rear Wiper Washer Switch Reference Voltage | 1 | 1 | -- | -- |
Rear Wiper Washer Switch Signal | 1 | 1 | 1 | -- |
Rear Washer Pump Relay Control | B3811 | B3811 | -- | -- |
Rear Washer Pump Control | 2 | 2 | 3 | -- |
Rear Washer Pump Ground | -- | 2 | -- | -- |
1. Rear wiper washer inoperative 2. Rear washer pump inoperative 3. Rear washer pump always on | ||||
Circuit/System Description
Battery positive voltage is supplied to the coil and switch sides of the rear washer relay. The body control module (BCM) energizes the relay by grounding the relay coil through the relay control circuit. When the relay is energized, the relay switch is closed and battery positive voltage is supplied to the washer pump control circuit.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Rear Wiper/Washer System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, verify the rear wiper motor operates using the rear washer switch.
- If the rear washer pump does not operate properly, refer to the Rear Washer Pump Circuit Test.
| ⇒ | If the rear wiper does not operate normally, refer to Rear Wiper System Malfunction . |
Circuit/System Testing
Rear Washer Pump Circuit Test
- Ignition OFF, disconnect the REAR/WPR relay.
- Ignition ON, verify that a test lamp does not illuminate between the washer pump control circuit terminal 30 and ground.
- Disconnect the harness connector at the rear washer pump.
- Test for less than 1.0 ohm between the rear washer pump ground circuit terminal A and ground.
- Connect the harness connector at the rear washer pump.
- Connect a 20A fused jumper wire between the B+ circuit terminal 87 and the washer pump control circuit terminal 30. Verify the rear washer pump is activated.
- Connect a test lamp between the B+ circuit terminal 85 and the relay control circuit terminal 86.
- Operate the rear washer switch ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, test or replace the REAR/WPR relay.
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the rear washer pump does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the rear washer pump. |
| ⇒ | If the test lamp is always ON, test the relay 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, programming, and setup |
