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 (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, observe the scan tool Internal Trunk/Liftgate Switch parameter while pressing the open switch on the mode/release switch. The reading should change between Active and Inactive.
• If not the specified value, refer to Liftgate Release Malfunction (Manual) (Liftgate Release Malfunction (Manual)).
2. Verify the front wipers operate in all modes.
• If the front wipers do not operate in all modes, refer to Windshield Wiper System Malfunction (Windshield Wiper System Malfunction).
3. 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 wipe cycles will occur after the switch is released.
• If the rear wiper motor and the rear washer pump are inoperative, refer to Multifunction Switch Circuit Test.
• If the rear washer pump operates normal and the rear wiper motor is inoperative, refer to the Rear Wiper Motor Circuit Malfunction.
• If the rear wiper motor operates and the rear washer pump is inoperative, refer to Rear Washer System Malfunction (Rear Washer System Malfunction).
Circuit/System Testing
Multifunction Switch Circuit Malfunction
1. Ignition OFF, disconnect the harness connector X1 at the S80 Window Wiper/Washer Switch.
2. Test for less than 5 ohm between the ground circuit terminal 2 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance and a short to voltage. If the circuit tests normal, replace the K9 BCM.
3. Disconnect the harness connector X2 at the K9 BCM.
4. Test for less than 5 ohm between the signal circuit terminal 4 X1 at the S80 Window Wiper/Washer Switch harness connector and the X2 harness connector terminal 12 at the K9 BCM.
• If greater than the specified value, test the signal circuit for an open/high resistance and a short to voltage.
5. Test for infinite resistance between the control circuit terminal 4 X1 at the S80 Window Wiper/Washer Switch harness connector and ground.
• If the value is not within the specified range, test the control circuit for a short to ground.
6. If all circuits test normal, replace the S80 Window Wiper/Washer Switch.
Rear Wiper Motor Circuit Malfunction
1. Ignition OFF, disconnect the harness connector at the M45 Rear Wiper Motor.
2. Test for less than 5 ohm 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 ohm between the control circuit terminal 4 and ground.
• If greater than the specified range, test the control circuit for an open/high resistance.
4. 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 and 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 the ground circuit terminal 3.
6. Using the S80 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 B at the X50A Fuse Block - Underhood.
2. Test for 60-200 ohm between control circuit terminal 5 C and ground circuit terminal 5 B.
• 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 12 V. 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.
Static Test
1. Ignition OFF, remove the S80 Window Wiper/Washer Switch.
2. Test for 580-730 ohm between the signal terminals 2 and 4 at the S80 Window Wiper/Washer Switch in the Low position.
• If the resistance is not within the specified range, replace the S80 Window Wiper/Washer Switch.
3. Test for 1.80-2.20 kohm between the signal terminals 2 and 4 at the S80 Window Wiper/Washer Switch in the intermittent position.
• If the resistance is not within the specified range, replace the S80 Window Wiper/Washer Switch.
Note: If the switch tests open in any switch position other than OFF, test the signal circuits for a short to voltage before replacing the switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Rear Window Wiper Motor Replacement (Equinox) (Rear Window Wiper Motor Replacement)Rear 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, setup, and programming