Rear Wiper Washer System Malfunction
Rear Wiper Washer System Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
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
Wiper/Washer Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Rear Wiper/Washer System Description and Operation (Rear Wiper/Washer System Description and Operation)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, verify the rear wiper motor operates using the rear washer switch.
• If the rear wiper does not operate normally, refer to Rear Wiper System Malfunction (Rear Wiper System Malfunction).
2. If the rear washer pump does not operate properly, refer to the Rear Washer Pump Circuit Test.
Circuit/System Testing
1. Ignition OFF, disconnect the REAR/WPR relay.
2. Ignition ON, verify that a test lamp does not illuminate between the washer pump control circuit terminal 30 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
3. Disconnect the harness connector at the rear washer pump.
4. Test for less than 1.0 ohm between the rear washer pump ground circuit terminal A and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
5. Connect the harness connector at the rear washer pump.
6. 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.
• 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.
7. Connect a test lamp between the B+ circuit terminal 85 and the relay control circuit terminal 86.
8. Operate the rear washer switch ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
• 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.
9. If all circuits test normal, replace the REAR/WPR relay.
Component Testing
1. Ignition OFF, disconnect the relay.
2. Test for 60-200 ohms between terminals 85 and 86.
• If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the relay.
4. Test for less than 2 ohms between terminals 30 and 87A.
• If greater than the specified range, replace the relay.
5. Install a 10A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.
• If greater than the specified range, replace the relay.
Component Testing
1. Ignition OFF, disconnect the relay.
2. Test for 60-200 ohms between terminals 85 and 86.
• If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals:
* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87
• If not the specified value, replace the relay.
4. Test for less than 2 ohms between terminals 30 and 87A.
• If greater than the specified range, replace the relay.
5. Install a 10A fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.
• If greater than the specified range, replace the relay.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Rear Window Washer Pump Replacement (Rear Window Washer Pump Replacement)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, programming, and setup