Circuit/System Testing

2019 Chevrolet Tahoe LS, 4WD, Gas/EthanolSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2018 Chevrolet Sonic. However, it is still accessible from the selected car via links, so may be relevant.

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 10 Ω between the low reference circuit terminal 2 and ground.
    • If 10 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.
    • Go to next step: If less than 10 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.
    • Go to next step: 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.
      • Go to next step: 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.
    • Go to next step: 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 harness connector at the G24 Windshield Washer Pump. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal 2 and ground.
    • 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.
    • Go to next step: If less than 10 Ω 
  3. Connect a test lamp between the control circuit terminal 1 and the ground circuit terminal 2, ignition ON.
  4. Verify the test lamp does NOT turn ON and OFF when commanding the Windshield 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.

    • Go to next step: If the test lamp does not turn ON and OFF 
  5. Ignition OFF, connect the harness connector at the G24 Windshield Washer Pump. Disconnect the X2 harness connector at the X50A Fuse Block - Underhood, It may take up to 2 min for all vehicle systems to power down.
  6. Test for less than 10 Ω between the ground circuit terminal C5 and ground.
    • 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.
    • Go to next step: If less than 10 Ω 
  7. Ignition ON.
  8. 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 the control circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the G24 Windshield Washer Pump.
    • Go to next step: If the G24 Windshield Washer Pump is not activated 
  9. Disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
  10. Connect a 20 A fused jumper wire between the control circuit terminal G3 and B+.
  11. 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 harness connector at the G24 Windshield Washer Pump.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than Infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If 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, replace the G24 Windshield Washer Pump.
    • Go to next step: If the G24 Windshield Washer Pump activates 
  12. Ignition OFF, connect the X1 harness connector at the X50A Fuse Block - Underhood. Disconnect the X4 harness connector at the K9 Body Control Module, ignition ON.
  13. Verify the G24 Windshield Washer Pump is not activated.
    • If the G24 Windshield Washer Pump is activated 
    1. Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block - Underhood, ignition ON.
    2. Test for less than 1 V between the control circuit terminal G9 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.
    • Go to next step: If the G24 Windshield Washer Pump is not activated 
  14. Connect a 10 A fused jumper wire between the control circuit terminal 14 and B+.
  15. 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 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: 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.
    • Go to next step: If the G24 Windshield Washer Pump activates 
  16. Replace the K9 Body Control Module.
RENDER: 1.0x

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When to See a Mechanic

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

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.