Rear Wiper System Malfunction
Rear Wiper 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 body control module (BCM) controls the single speed rear wiper motor by its active high output to the external rear wiper motor relay. When the BCM activates its output and applies battery to the coil of the relay, the relay energizes, allowing battery voltage from the fuse to be applied through the switched contacts of the rear wiper motor relay to the control input of the rear wiper motor. The motor then operates continuously at low speed.
Diagnostic Aids
Verify the Trunk/Liftgate is closed during Circuit/System Verification.
Reference Information
Schematic Reference
Wiper/Washer Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Sunshade - Left Front
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
Using the S82 window wiper/washer switch, press and release the rear window washer switch. The rear window wiper motor and pump should operate continuously for as long as the wash switch is pressed and several wiper cycles will occur after the switch is released.
If the rear wiper motor operates and the rear washer pump is inoperative, refer to Washer Malfunction Washer Malfunction.
If the rear wiper motor and the rear washer pump are inoperative, refer to Rear Wiper/Washer Switch Circuit Test.
If the rear washer pump operates normal and the rear wiper motor is inoperative, refer to the Rear Wiper Motor Circuit Test.
Circuit/System Testing
Rear Wiper/Washer Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the S82 windshield wiper/washer switch.
2. Test for less than 5 ohms between the low reference terminal 2 and ground.
• If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K9 BCM.
3. Test for greater than 10 V between the signal circuit terminal 4 and ground.
• If less than the specified value, test the signal circuit for an open/high resistance.
4. If all circuits test normal, replace the S82 windshield wiper/washer switch.
Rear Wiper Motor Circuit Test
1. Ignition OFF, disconnect the harness connector at the M45 rear wiper motor.
2. Test for less than 5 ohms between the ground circuit terminal 3 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Test for less than 5 ohms between the control circuit terminal 4 and ground.
• If greater than the specified range, test the control circuit for an open/high resistance.
4. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance on a short to ground. If all circuits test normal, replace the X50A fuse block - underhood.
5. Install a test lamp between the control circuit terminal 4 and ground.
6. Using the S82 window wiper/washer switch, command the rear wiper ON and OFF. The test lamp should turn ON and OFF as commanded. Observe this in the switch position continuous and intermittent.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the K9 BCM.
7. If all circuits test normal, test or replace the X50A fuse block - underhood.
Component Testing
Relay Test
1. Ignition OFF, disconnect the harness connector X2 at the X50A fuse block - underhood.
2. Test for 60-200 ohms between control circuit terminal C5 and ground.
• If all circuits test normal, test or replace the X50A fuse block - underhood.
Dynamic Test
1. Ignition OFF, disconnect the harness connector at the M45 rear wiper motor.
2. Install a 25 A fused jumper wire between the control terminal 4 and B+. Install a jumper wire between the ground terminal 3 and ground.
3. Verify the M45 rear wiper motor is operating.
• If the M45 rear wiper motor is not operating, replace the M45 rear wiper motor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the 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)
* Rear Window Wiper Motor Replacement (Equinox) Rear Window Wiper Motor ReplacementRear Window Wiper Motor Replacement (Terrain) Rear Window Wiper Motor Replacement
* Windshield Wiper and Washer Switch Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, programming and setup