Rear Wiper System Malfunction

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Diagnostic Fault Information

Circuit Number	Circuit Descriptio	Short to n Ground	Open/High Resistance	Short to Voltage	Signal Performan
3040	B+	1	1	—	—
391	Signal	1	1	1	B10C8 23
2856	Serial Data	U152E	U152E	U152E	—
2050	Ground	—	1	—	—
6009	Ground	—	1	—	—
1. Rear Wiper Inoperative

Circuit/System Description The windshield washer system allows the driver to clean the vehicle’s windshield or rear window using a discrete switch. The washer system uses the S78 Turn Signal Switch as the primary means of driver control. The S78 Turn Signal Switch is a discrete input to the K9 Body Control Module. The K9 Body Control Module communicates with the K219 Lighting Control Module over CAN to control G24 Windshield Washer Pump activation. The K9 Body Control Module also communicates with the K219 Lighting Control Module to control B+ to the M45 Rear Wiper Motor during operation. The windshield washer uses a single windshield washer pump to provide fluid for both the front and rear washers. Changing the polarity of the motor will cause it to spin in opposite directions, feeding fluid to the front or rear. When rear washers are requested, the K219 Lighting Control Module applies voltage to the rear window washer pump relay control circuit. This causes the contacts in the KR6 Rear Window Washer Pump Relay to close and supplies voltage to the G24 Windshield Washer Pump. Ground for the G24 Windshield Washer Pump is provided through the KR11 Windshield Washer Pump Relay, which is switched to ground in it’s at-rest state. Reference Information Schematic Reference Wiper/Washer Schematics Connector End View Reference Master Electrical Component List Description and Operation Wiper/Washer System Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

Verify there are no communication related DTCs set in the K9 Body Control Module or the K219 Lighting Control Module. ⇒ If there are any DTCs set Refer to: Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If there are no DTCs set
Remove the rear wiper arm: Rear Window Wiper Arm Replacement
Verify that the M45 Rear Wiper Motor operates when requested and stops in the proper park position when turned off. ⇒ Wiper doesn’t operate Refer to Circuit/System Testing ⇒ Wiper operates but doesn’t stop in proper park position Replace the M45 Rear Wiper Motor. ⇓ Wiper operates and stops in proper park position
A fault is not currently present and may be an intermittent condition. Circuit/System Testing Windshield Wiper and Washer Switch Malfunction
Ignition OFF and all vehicle systems OFF, disconnect the connector at the S78 Turn Signal Switch. It may take up to 2 min for all vehicle systems to power down.
Verify a test lamp illuminates between the low reference circuit terminal 1 and B+. ⇒ If test lamp does not illuminate 2.1. Test circuit 6009 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 2.2. Replace the K9 Body Control Module. ⇓ If test lamp illuminates
Ignition ON.
Test for 4.8–5.2 V between circuit terminal 4 and ground. ⇒ If greater than 5.2 V 4.1. Test circuit 94 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 4.2. Replace the K9 Body Control Module. ⇒ If less than 4.8 V 4.1. Test circuit 94 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 4.2. Test circuit 94 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 4.3. Replace the K9 Body Control Module. ⇓ If 4.8–5.2 V
Test or replace the S78 Turn Signal Switch. Rear Window Wiper Malfunction
Ignition OFF, and all vehicle systems OFF, disconnect the connector at the M45 Rear Window Wiper Motor. It may take up to 2 min for all vehicle systems to power down.
Verify a test lamp illuminates between ground circuit terminal 1 and B+. ⇒ If test lamp does not illuminate Repair the open/high resistance on circuit 2050 or ground connection ⇓ If test lamp illuminates
Verify a test lamp illuminates between B+ circuit terminal 3 and ground. ⇒ If the test lamp does not illuminate and circuit fuse is OK 3.1. Test circuit 3040 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 3.2. Refer to: Retained Accessory Power Malfunction ⇒ If the test lamp does not illuminate and circuit fuse is open 3.1. Test circuit 3040 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Replace the X53A Body Wiring Harness Junction Block — Rear. ⇓ If the test lamp illuminates
Replace the M45 Rear Wiper Motor. Component Testing Windshield Wiper/Washer Switch
Ignition OFF, disconnect the harness connector at the S78 Turn Signal Switch.
Test for infinite resistance between the signal terminal 4 and the low reference terminal 1 with the switch in the open position. ⇒ If less than infinite resistance Replace the S78 Turn Signal Switch. ⇓ If infinite resistance
Test for 4k-4.42k Ω between the signal terminal 4 and the low reference terminal 1 with the switch in the intermittent position. ⇒ If not 4k-4.42k Ω Replace the S78 Turn Signal Switch. ⇓ If 4k-4.42k Ω
Test for 1.2k-1.34k Ω between the signal terminal 4 and the low reference terminal 1 with the switch in the low position. ⇒ If not 1.2k-1.34k Ω Replace the S78 Turn Signal Switch ⇓ If 1.2k-1.34k Ω
All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Windshield Washer Pump Replacement Turn Signal Switch Replacement Control Module References for body control module replacement, programming and setup.