Washer Malfunction
Washer 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
During the Wash mode, if the rear washer switch is momentarily turned to ON, the rear wiper will wipe the rear window 3-5 times and then park. However, if the rear washer switch is held to ON, the rear window wipers will continue to operate until the switch is released. The REAR WSW relay receives voltage on the coil and switched sides from the WSW PUMP fuse. When the rear washer is activated, the BCM supplies ground to the switched side of the REAR WSW relay, activating the relay. The relay then supplies voltage to the Windshield Washer Fluid pump. The Windshield Washer Fluid pump receives a path to ground through the WSW PUMP relay. The Windshield Washer Fluid pump is bidirectional and provides washer fluid for both the front and rear windshields. The direction of the Windshield Washer Fluid pump is determined by the state of the REAR WSW relay and the WSW PUMP relay.
Reference Information
Schematic Reference
Wiper/Washer Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
Description and Operation
Wiper/Washer System Description and Operation 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, 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 rear wipers turn on.
• If the washer pump does not activate, refer to Washer Pump Circuit Malfunction.
• If the rear wipers do not turn on, refer to Rear Wiper System Malfunction (Rear Wiper System Malfunction).
Circuit/System Testing
Windshield Wiper/Washer Switch Circuit Malfunction
1. Ignition OFF, disconnect the harness connector at the Rear Windshield Wiper/Washer switch.
2. Ignition ON, test for 12 volts between accessory voltage circuit terminal 5 and ground.
• If not the specified value, test the accessory voltage circuit terminal 5 for a short to ground or open high resistance. 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 5 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the control circuit terminal 5 and ground. 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 B of Windshield Washer Fluid Pump connector while activating washers.
• 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.
3. Install a test light between control circuit terminal B and ground circuit terminal A 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 5 and the control terminal 3.
• If not the specified value, replace the multifunction switch.
2. With the WASH switch in the closed position, test for less than 2 ohm between the Accessory Voltage terminal 5 and the control terminal 3.
• 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 (Verification Tests) after completing the diagnostic procedure.
* Turn Signal Multifunction Switch Replacement (Service and Repair)
* Underhood Electrical Center or Junction Block Replacement (Underhood Electrical Center or Junction Block Replacement)
* Washer Pump Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming