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Tahoe / Yukon Service Manual

Windshield 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
1715 Signal B1176 11 B1176 13 B1176 12 —
1714 Signal B1267 11 B1267 15 B1267 15 B1267 92
91 Control 1,2 1,2 4 —
860 Control — 2 2 —
196 Control 3 3 — —
95 Control 1, 2 1 4 —
92 Control 1, 2 2 4 —
6009 Low Reference — B1267 15 — —
250 Ground — 1, 2, 3 — —
1. Delay or Low Speed Wipers Inoperative 2. High Speed Wipers Inoperative 3. Wipers Do Not Park 4. Wipers Always ON

Circuit/System Description The windshield wipers system allows the driver to clear the vehicle’s windshield using a discrete switch or through an automatic rain sensing system. The wiper systems uses the S78 Turn SIgnal Switch as the primary means of driver control, along with the B117A Windshield Outside Moisture/Ambient Light and Humidity Sensor to modulate intermittent wiper operation. 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, and with the B117A Windshield Outside Moisture/Ambient Light and Humidity Sensor over LIN, to control wiper activation. 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 Testing Windshield Wiper Switch Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the connector at the S78 Turn SIgnal Switch.
  2. Verify a test lamp illuminates between the low reference circuit terminal 8 and B+. ⇒ If the test lamp does not illuminate 2.1. Test circuit 6009 for an open/high resistance. ⇒ If open/high resistance is found, repair the fault on the circuit. ⇓ If open/high resistance is not found 2.2. Replace the K9 Body Control Module ⇓ If the test lamp illuminates
  3. Ignition ON.
  4. Verify the scan tool Windshield Wiper Switch parameter is not High. ⇒ If High 4.1. Test circuit 1715 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. Replace the S78 Turn SIgnal Switch. ⇓ If not High
  5. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the low reference circuit terminal 8.
  6. Verify the scan tool Windshield Wiper Switch parameter is High. ⇒ If not High 6.1. Test circuit 1715 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 6.2. Test circuit 1715 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. 6.3. Replace the K219 Lighting Control Module. ⇓ If High
  7. Test for 4.8–5.2 V between the signal circuit terminal 10 and ground. ⇒ If less than 4.8 V 7.1. Test circuit 1714 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. 7.2. Test circuit 1714 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. 7.3. Replace the K9 Body Control Module. ⇒ If greater than 5.2 V 7.1. Test circuit 1714 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. 7.2. Replace the K9 Body Control Module. ⇓ If 4.8–5.2 V
  8. Test or replace the S78 Turn SIgnal Switch. Windshield Wiper Motor Malfunction
  9. Ignition OFF and all vehicle systems OFF, disconnect the X1 connector at the X50A Fuse Block - Underhood.
  10. Verify a test lamp illuminates between ground circuit terminal A4 and B+. ⇒ If the test lamp does not illuminate Repair the open/high resistance on circuit 250 or ground connection. ⇓ If the test lamp illuminates
  11. Connect the X1 connector at the X50A Fuse Block - Underhood, disconnect the connector at the M75 Windshield Wiper Motor.
  12. Test for less than 10 Ω between the ground circuit terminal 4 and ground. ⇒ If 10 Ω or greater Repair the open/high resistance on circuit 150 or ground connection. ⇓ If less than 10 Ω
  13. Ignition ON.
  14. Verify the scan tool Windshield Wiper Mode parameter is not Parked. ⇒ If Parked 6.1. Test circuit 196 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. 6.2. Replace the K219 Lighting Control Module. ⇓ If not Parked
  15. Install a 3 A fused jumper wire between the signal circuit terminal 3 and ground circuit terminal 4.
  16. Verify the scan tool Windshield Wiper Mode parameter is Parked. ⇒ If not Parked 8.1. Test circuit 196 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. 8.2. Test circuit 196 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. 8.3. Replace the K219 Lighting Control Module. ⇓ If Parked
  17. Connect a test lamp between the following control circuits and ground, ignition ON. Windshield Wiper Motor High Speed Control Circuit Terminal 1 Windshield Wiper Motor Low Speed Control Circuit Terminal 2
  18. Verify the test lamp does NOT turn ON and OFF when commanding the Windshield Wiper High and Low with a scan tool. ⇒ If the test lamp turns ON and OFF for both terminals Test or replace the M75 Windshield Wiper Motor. ⇓ If the test lamp does not turn ON and OFF for one or both terminals
  19. Ignition OFF, connect the harness connector at the M75 Windshield Wiper Motor. Disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
  20. Connect a 20 A fused jumper wire between the control circuit terminals listed below, one at a time, and B+. Terminal H5 Terminal H6
  21. Verify the M75 Windshield Wiper Motor activates. ⇒ If the M75 Windshield Wiper Motor does not activate 13.1. Test the following circuits for a short to ground: Circuit 92 Circuit 95 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 13.2. Test the following circuits for an open/high resistance: Circuit 92 Circuit 95 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 13.3. Replace the M75 Windshield Wiper Motor. ⇓ If the M75 Windshield Wiper Motor activates
  22. Ignition OFF, connect the X1 connector at the X50A Fuse Block – Underhood. Disconnect the X2 connector at the K219 Lighting Control Module, ignition ON.
  23. Verify the M75 Windshield Wiper Motor low speed is not activated. ⇒ If the M75 Windshield Wiper Motor low speed is activated 15.1. Test circuit 91 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 15.2. Replace the X50A Fuse Block — Underhood. ⇓ If the M75 Windshield Wiper Motor low speed is not activated
  24. Verify the M75 Windshield Wiper Motor High Speed is not activated. ⇒ If the M75 Windshield Wiper Motor high speed is activated 16.1. Test circuit 860 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. 16.2. Replace the X50A Fuse Block — Underhood. ⇓ If the M75 Windshield Wiper Motor high speed is not activated
  25. Connect a 10 A fused jumper wire between the control circuit terminal 12 X2 and B+.
  26. Verify the M75 Windshield Wiper Motor activates. ⇒ If the M75 Windshield Wiper Motor does not activate 18.1. Test circuit 91 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. 18.2. Test circuit 91 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. 18.3. Replace the X50A Fuse Block — Underhood. ⇓ If the M75 Windshield Wiper Motor activates
  27. Connect a 10 A fused jumper wire between the control circuit terminal 21 X2 and ground.
  28. Verify the M75 Windshield Wiper Motor activates. ⇒ If the M75 Windshield Wiper Motor does not activate 20.1. Test circuit 860 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. 20.2. Test circuit 860 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. 20.3. Replace the X50A Fuse Block — Underhood. ⇓ If the M75 Windshield Wiper Motor activates
  29. Replace the K219 Lighting Control Module. Repair Instructions Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Windshield Wiper System Module Replacement Turn Signal Switch Replacement Control Module References for Lighting Control Module replacement, programming and setup.