Circuit/System Testing

2015 Buick Regal Base, 2.0L Eng VIN X, AWDSECTION Circuit/System Testing

Windshield Wiper/Washer Switch Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S82 Windshield Wiper/Washer Switch. It may take up to 11 min for all vehicle systems to power down.
  2. Test for less than 10Ω between the low reference circuit terminal 2 and ground.
    • If 10Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for less than 2Ω in the low reference circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If less than 10Ω 
  3. Ignition ON.
  4. Verify the scan tool Windshield Wiper High Speed Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • If Inactive 
  5. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2.
  6. Verify the scan tool Windshield Wiper High Speed Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1V between the signal circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If Active 
  7. Test for greater than 8V between the signal circuit terminal 3 and ground.
    • If less than 8V 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit and ground
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If 8V or greater 
  8. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
  9. Test for less than 1V between the S82 Windshield Wiper/Washer Switch signal circuit terminal 3 and ground.
    • If 1V or greater 

      Repair the short to voltage on the circuit.

    • If less than 1V 
  10. Test or replace the S82 Windshield Wiper/Washer Switch.

Windshield Wiper Motor Malfunction

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the M75 Windshield Wiper Motor. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10Ω between the ground circuit terminal D and ground.
    • If 10Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2Ω in the ground circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, repair the open/high resistance in the ground connection.
    • If less than 10Ω 
  3. Ignition ON.
  4. Verify the scan tool Windshield Wiper Park Switch parameter is Inactive.
    • If not Inactive 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the signal circuit terminal C and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • If Inactive 
  5. Install a 3A fused jumper wire between the signal circuit terminal C and the ground circuit terminal D.
  6. Verify the scan tool Windshield Wiper Park Switch parameter is Active.
    • If not Active 
    1. Ignition OFF, remove the jumper wire, disconnect the harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1V between the signal circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If Active 
  7. Ignition OFF and all vehicle systems OFF, disconnect the KR12B Windshield Wiper Relay. It may take up to 2 min for all vehicle systems to power down.
  8. Test for less than 10Ω between the ground circuit terminals listed below and ground.
    • terminal 85
    • terminal 87A
    • If 10Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2Ω in the ground circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, repair the open/high resistance in the ground connection.
    • If less than 10Ω 
  9. Ignition ON.
  10. Verify a test lamp illuminates between the B+ circuit terminal 87 and the ground circuit terminal 87A.
    • If the test lamp does not illuminate and the circuit fuse is good 

      Replace the X50A Fuse Block - Underhood.

    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp. Disconnect the KR12C Windshield Wiper Speed Control Relay.
    2. Test for infinite resistance between the control circuits listed below and ground.
      • Terminal 87A
      • Terminal 87
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the M75 Windshield Wiper Motor
    • If the test lamp illuminates 
  11. Connect a test lamp between the control circuit terminal 86 and the ground circuit terminal 85.
  12. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1V between the control circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K9 Body Control Module.
    • If the test lamp turns ON and OFF 
  13. Ignition OFF, connect the KR12B Windshield Wiper Relay and disconnect the KR12C Windshield Wiper Speed Control Relay, ignition ON.
  14. Test for less than 10Ω between the control circuit terminal 30 and ground.
    • If 10Ω or greater 

      Test or replace the KR12B Windshield Wiper Relay.

    • If less than 10Ω 
  15. Connect a test lamp between the control circuit terminal 30 and ground.
  16. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.
    • If the test lamp does not turn ON and OFF 

      Test or replace the KR12B Windshield Wiper Relay.

    • If the test lamp turns ON and OFF 
  17. Verify a test lamp illuminates between the B+ circuit terminal 85 and ground.
    • If the test lamp does not illuminate 

      Replace the X50A Fuse Block - Underhood.

    • If the test lamp illuminates 
  18. Connect a test lamp between the B+ circuit terminal 85 and the control circuit terminal 86.
  19. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper High Speed Relay High and Off with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1V between the control circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V
    3. Ignition OFF.
    4. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K9 Body Control Module.
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K9 Body Control Module.
    • If the test lamp turns ON and OFF 
  20. Ignition OFF, connect the KR12C Windshield Wiper Speed Control Relay.
  21. Connect a test lamp between the M75 Windshield Wiper Motor control circuit terminal B and ground circuit terminal D, ignition ON.
  22. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper Motor Relay Low and Off with a scan tool.
    • If the test lamp is always OFF  
    1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, test or replace the KR12C Windshield Wiper Speed Control Relay.
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay, ignition ON.
    2. Test for less than 1V between the control circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, test or replace the KR12C Windshield Wiper Speed Control Relay.
    • If the test lamp turns ON and OFF 
  23. Connect a test lamp between the M75 Windshield Wiper Motor control circuit terminal A and ground circuit terminal D, ignition ON.
  24. Verify the test lamp turns ON and OFF when commanding the Windshield Wiper High Speed Relay High and Off with a scan tool.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the control circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, test or replace the KR12C Windshield Wiper Speed Control Relay.
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp, disconnect the KR12C Windshield Wiper Speed Control Relay, ignition ON.
    2. Test for less than 1V between the control circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, test or replace the KR12C Windshield Wiper Speed Control Relay.
    • If the test lamp turns ON and OFF 
  25. Test or replace the M75 Windshield Wiper Motor.
RENDER: 1.0x

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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