Circuit/System Testing

2019 Chevrolet Trax Premier, AWDSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2018 Chevrolet Trax and 2018 Buick Encore. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K8 Blower Motor Control Module. It may take up to 10 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal 5 and ground.
    • If 10 Ω or greater 
    1. Ignition OFF.
    2. 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. Verify a test lamp illuminates between the B+ circuit terminal 6 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp.
    2. Test for infinite resistance between the B+ circuit terminal 6 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Disconnect the X2 harness connector at the K8 Blower Motor Control Module and disconnect the harness connector at the M8 Blower Motor.
    4. Test for infinite resistance between the M8 Blower Motor B+ circuit terminal 2 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, test or replace the M8 Blower Motor.
    • Go to next step: If the test lamp illuminates 
  4. Ignition ON. Test for less than 1 V between the control circuit terminal 3 and ground.
    • If 1 V or greater 
    1. Ignition OFF, disconnect the X2 harness connector at the K33 HVAC Control Module. Ignition ON.
    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, replace the K33 HVAC Control Module
    • Go to next step: If less than 1 V 
  5. Ignition OFF and all vehicle systems OFF, disconnect the X2 harness connector at the K33 HVAC Control Module. It may take up to 10 min for all vehicle systems to power down.
  6. Test for infinite resistance between the control circuit terminal 15 and ground.
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  7. 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

    • Go to next step: If less than 2 Ω 
  8. NOTE:

    Verify the ignition is OFF before connecting the blower motor control module or incorrect test results may occur.

  9. Ignition OFF, connect all harness connectors. Ignition ON.
  10. While backprobing terminal 3 X1 at the K8 Blower Motor Control Module, test for greater than 1 V between the control circuit and ground.
    • If less than 1 V 

      Replace the K8 Blower Motor Control Module.

    • Go to next step: If 1 V or greater 
  11. Verify the voltage decreases and increases while using the controls to change the blower speed selection.
    • If the voltage does not decrease and increase as the blower speed selection is changed 

      Replace the K33 HVAC Control Module.

    • Go to next step: If the voltage decreases and increases as the blower speed selection is changed 
  12. Ignition OFF, disconnect the harness connector at the M8 Blower Motor, ignition ON and blower ON.
  13. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate 
    1. Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor Control Module.
    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 K8 Blower Motor Control Module.
    • Go to next step: If the test lamp illuminates 
  14. Connect a test lamp between control circuit terminal 1 and B+ circuit terminal 2.
  15. Verify the test lamp becomes progressively brighter as the blower speed is increased and progressively dimmer as the blower speed is decreased.
    • If the test lamp does not illuminate 
    1. Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor Control Module, 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.
      • Go to next step: If less than 1 V
    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 K8 Blower Motor Control Module.
    • If the test lamp illuminates, but does not change in brightness 
    1. Ignition OFF, disconnect the X2 harness connector at the K8 Blower Motor 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 K8 Blower Motor Control Module.
    • Go to next step: If the test lamp changes in brightness as the blower speed is changed 
  16. Test or replace the M8 Blower 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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