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Home >> GMC >> 2017 >> Terrain SL, Gas >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Wiper/Washer Systems >> Wiper System And Washer System >> Diagnostic Information and Procedures >> DTC B3873: Front Washer Relay Circuit >> Circuit/System Testing
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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 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
    • If 5 Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • If less than 5 Ω 
  3. Ignition ON.
  4. Verify the scan tool Windshield Washer 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 5 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 3 A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 2.
  6. Verify the scan tool Windshield Washer 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 1 V between the signal circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Test for less than 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module.
    • If Active 
  7. Test or replace the S82 Windshield Wiper/Washer Switch.

Windshield Washer Pump Malfunction

  1. Ignition OFF, and all vehicle systems OFF. Disconnect the X2 and X3 harness connectors at the X50A Fuse Block - Underhood. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 10 Ω between each of the ground circuits listed below and ground.
    • Terminal C8 X2
    • Terminal G1 X3
    • If 10 Ω or greater 
    1. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the ground connection.
    • If less than 10 Ω 
  3. Test for infinite resistance between each of the control circuit terminals below and ground.
    1. Terminal B1
    2. Terminal B2
    • If less than Infinite resistance 

      Repair the short to ground on the circuit.

    • If infinite resistance 
  4. Disconnect the harness connector at the G24 Windshield Washer Pump and connect the X2 and X3 harness connectors at the X50A Fuse Block - Underhood.
  5. Test for less than 10 Ω between the control circuit terminal 1 and the control circuit terminal 2.
    • If 10 Ω or greater 
    1. Ignition OFF, disconnect the X3 harness connectors at the X50A Fuse Block - Underhood.
    2. Test for less than 2 Ω in each of the control circuits listed below end to end.
      • Terminal B1
      • Terminal B2
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the X50A Fuse Block - Underhood.
    • If less than 10 Ω 
  6. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2, ignition ON.
  7. Verify the test lamp does NOT turn ON and OFF when commanding the Rear Washer Relay Active and Inactive with a scan tool.
    • If the test lamp turns ON and OFF 

      Test or replace the G24 Windshield Washer Pump.

    • If the test lamp does not turn ON and OFF 
  8. Ignition OFF, connect the harness connector at the G24 Windshield Washer Pump, ignition ON.
  9. Verify the G24 Windshield Washer Pump is not activated.
    • If the G24 Windshield Washer Pump is activated 
    1. Ignition OFF, disconnect the harness connector at the G24 Windshield Washer Pump, ignition ON.
    2. Test for less than 1 V between each of the control circuits listed below and ground.
      • Terminal 1
      • Terminal 2
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the G24 Windshield Washer Pump.
    • If the G24 Windshield Washer Pump is not activated 
  10. Ignition OFF, disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
  11. Verify the G24 Windshield Washer Pump is NOT activated.
    • If the G24 Windshield Washer Pump is activated 
    1. Ignition OFF, disconnect the X4 harness connector at the X50A Fuse Block - Underhood, ignition ON.
    2. Test for less than 1 V between the control circuit terminal K4 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the X50A Fuse Block - Underhood.
    • If the G24 Windshield Washer Pump is not activated 
  12. Connect a 10 A fused jumper wire between the control circuit terminal 14 and B+.
  13. Verify the G24 Windshield Washer Pump activates.
    • If the G24 Windshield Washer Pump does not activate 
    1. Ignition OFF, remove the jumper wire, disconnect the X2 harness connector at the X50A Fuse Block - Underhood.
    2. Test for infinite resistance between the control circuit terminal K4 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If less than infinite resistance
    3. Test for less than 2 Ω in the control circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, test or replace the X50A Fuse Block - Underhood.
    • If the G24 Windshield Washer Pump activates 
  14. Replace the K9 Body Control Module.
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