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
The rear washer is activated based on an input from the rear washer switch. When the wiper portion of the rear wiper/washer switch is closed, B+ is applied to the REAR/WSW relay indicating rear washer operation is requested. With B+ applied to the relay coil, the relay is energized and B+ is supplied to the washer pump.
Reference Information
Schematic Reference
Wiper/Washer Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Rear Wiper/Washer System Description and Operation Rear Wiper/Washer System
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 operates normally using the rear wiper switch.
• If the rear wipers do not operate properly, refer to Rear Wiper System Malfunction Rear Wiper System Malfunction.
2. Operate the rear washers using the rear washer switch. The rear washer pump should activate.
Circuit/System Testing
1. Ignition OFF, disconnect the REAR/WSW relay.
2. Ignition ON, verify a test lamp does not illuminate between the control circuit terminal 87 and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage.
3. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 86 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 30 and ground.
• If the test lamp does not illuminate, replace the I/P fuse block.
5. Install a test lamp between the control circuit terminal 85 and ground.
6. Command the rear washers ON and OFF using the rear washer switch. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, test or replace the I/P switch assembly.
• If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the I/P switch assembly.
7. Ignition OFF, disconnect the harness connector at the rear window washer fluid pump.
8. Test for less than 20 ohms between the ground circuit terminal A and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
9. Connect the harness connector at the rear window washer fluid pump.
10. Connect a 20 A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the rear window washer fluid pump is activated.
• If the rear window washer fluid pump does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the rear window washer fluid pump.
11. Disconnect the harness connector at the rear window wiper motor.
12. Rear wiper switch in the ON position, verify a test lamp illuminates between the signal circuit terminal C and ground.
• If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the I/P switch assembly.
13. If all circuits test normal, test or replace the REAR/WSW relay.
Component Testing
I/P Switch Assembly
1. Ignition OFF, disconnect the harness connector at the I/P switch assembly.
2. Rear washer switch OFF, test for infinite resistance between the ignition terminal 6 and the control terminal 12.
• If not the specified value, replace the I/P switch assembly.
3. Rear washer switch ON, test for less than 2 ohms between the ignition terminal 6 and the control terminal 12.
• If greater than the specified range, replace the I/P switch assembly.
Rear Window Washer Fluid Pump
1. Ignition OFF, disconnect the harness connector at the rear window washer fluid pump.
2. Install a 20 A fused jumper wire between the control terminal B and 12 V. Install a jumper wire between the ground terminal A and ground.
3. Verify the rear window washer fluid pump is activated.
• If the rear window washer fluid pump does not activate, replace the rear window washer fluid pump.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Rear Window Washer Pump Replacement (Acadia and Enclave) Rear Window Washer Pump Replacement (Acadia and Enclave)
* Turn Signal Multifunction Switch Replacement Turn Signal Multifunction Switch Replacement
* Instrument Panel Electrical Center or Junction Block Replacement Instrument Panel Electrical Center or Junction Block Replacement
* Accessory Switch Replacement Service and Repair
* Relay Replacement (Within an Electrical Center) Relay Replacement (Within an Electrical Center)Relay Replacement (Attached to Wire Harness) Relay Replacement (Attached to Wire Harness)