Circuit/System Testing

2018 Chevrolet Sonic Premier, 4D Sedan, Standard TransSECTION Circuit/System Testing
  1. Ignition OFF, and all vehicle systems OFF. 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.
  2. 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 
  3. Connect the X2 harness connector and disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
  4. Test for infinite resistance between each of the control circuit terminals listed below and ground.
    • Terminal G3
    • Terminal H3
    • If less than Infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  5. Connect the X1 harness connector at the X50A Fuse Block - Underhood. Disconnect the harness connector at the G24 Windshield Washer Pump, ignition ON.
  6. Test for less than 1 V between the control circuit terminals listed below and ground:
    • Terminal 1
    • Terminal 2
    • If 1 V or greater 
    1. Ignition OFF, disconnect the X1 harness connector at the X50A Fuse Block - Underhood.
    2. Test for less than 1 V between the control circuit and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, test or replace the X50A Fuse Block - Underhood.
    • Go to next step: If less than 1 V 
  7. Ignition OFF, and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down.
  8. Test for less than 10 Ω between the control circuit terminal 1 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF, disconnect the X1 harness connectors at the X50A Fuse Block - Underhood.
    2. 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 X50A Fuse Block - Underhood.
    • Go to next step: If less than 10 Ω 
  9. Test for less than 10 Ω between the control circuit terminal 2 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF, disconnect the X1 harness connectors at the X50A Fuse Block - Underhood.
    2. 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 X50A Fuse Block - Underhood.
    • Go to next step: If less than 10 Ω 
  10. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2, ignition ON.
  11. Verify the test lamp does NOT turn ON and OFF when commanding the rear washer ON and OFF with the rear washer switch.
    • 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 
  12. Ignition OFF, connect the harness connector at the G24 Windshield Washer Pump. Disconnect the X2 harness connector at the X50A Fuse Block - Underhood, ignition ON.
  13. Connect a test lamp between the control circuit terminal G2 and ground.
  14. Verify the test lamp turns ON and OFF when commanding the rear washer ON and OFF with the rear washer switch.
    • If the test lamp is always OFF 
    1. Ignition OFF, remove the test lamp. Disconnect the X1 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.
      • 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 short to ground on the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module
    • If the test lamp is always ON 
    1. Ignition OFF, remove the test lamp. Disconnect the X1 harness connector at the K9 Body Control Module, ignition ON.
    2. Test for less than 1 V between the control circuit and ground.
      • If 2 Ω or greater, repair the short to voltage on the circuit.
      • If less than 2 Ω, replace the K9 Body Control Module
    • Go to next step: If the test lamp turns ON and OFF. 
  15. Test or replace the X50A Fuse Block - Underhood.
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

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.