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Circuit/System Testing

WARNING: This page is about a different car, the 2012 Chevrolet Volt. However, it is still accessible from the selected car via links, so may be relevant.

Dimmer Switch Malfunction

  1. Vehicle OFF, disconnect the harness connector at the S16 driver information center switch, vehicle in Service Mode.
  2. Verify a test lamp illuminates between the low reference circuit terminal 12 and B+.
    • If the test lamp does not illuminate 
    1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the low reference circuit terminal 12 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 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 the test lamp illuminates 
  3. Test for B+ between the B+ circuit terminal 11 and ground.
    • If less than B+ 
    1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module.
    2. Test for infinite resistance between the B+ reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the B+ 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 B+ 
  4. Verify a test lamp does not illuminate between the B+ circuit terminal 11 and ground.
    • If the test lamp illuminates 
    1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the B+ circuit terminal 11 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If the test lamp does not illuminate 
  5. Verify the scan tool LED Backlight Dimming Command parameter is greater than 40%.
    • If 40% or less 
    1. Vehicle OFF, disconnect the X2 harness connector at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the signal circuit terminal 10 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If greater than 40% 
  6. Install a 3 A fused jumper wire between the signal circuit terminal 10 and the B+ circuit terminal 11.
  7. Verify the scan tool LED Backlight Dimming Command parameter is less than 30%.
    • If 30% or greater 
    1. Vehicle OFF, disconnect the X2 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 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 less than 30% 
  8. Test or replace the S16 driver information center switch.

Interior Backlighting Malfunction

    NOTE:

    Each component with backlighting may need to be disconnected to isolate a short to voltage or short to ground. Use the schematics to identify the following:

    • Backlighting components the vehicle is equipped with
    • Each component's control and ground circuit terminals
    • Component locations on the backlighting control circuit
  1. Vehicle OFF, all doors closed, all accessories OFF, disconnect the harness connector at the component with inoperative backlighting. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 15 Ω between the appropriate ground circuit terminal and ground.
    • If 15 Ω or greater 
    1. Vehicle 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.
    • If less than 15 Ω 
  3. Connect a test lamp between the appropriate control circuit terminal and ground, vehicle in Service Mode.
  4. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Vehicle OFF, disconnect the X2 and X7 harness connectors 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 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 K9 body control module.
    • If the test lamp is always ON 
    1. Vehicle OFF, disconnect the X2 and X7 harness connectors at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If the test lamp turns ON and OFF 
  5. Test or replace the component with inoperative backlighting.

Vehicle ON/OFF Switch Backlighting Malfunction

  1. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S83 vehicle ON/OFF switch. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the ground circuit terminal 4 and ground.
    • If 5 Ω or greater 
    1. Vehicle 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.
    • If less than 5 Ω 
  3. Connect a test lamp between the control circuit terminal 8 and ground, vehicle in Service Mode, park lamps ON.
  4. Verify the test lamp changes from LOW to HIGH as the dimmer switch is activated from LOW to HIGH.
    • If the test lamp is always OFF 
    1. Vehicle OFF, disconnect the X7 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 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 K9 body control module.
    • If the test lamp is always ON full intensity 
    1. Vehicle OFF, disconnect the X7 harness connector at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If the test lamp changes from LOW to HIGH 
  5. Test or replace the S83 vehicle ON/OFF switch.

Switch Backlighting Malfunction

  1. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the appropriate switch listed below. It may take up to 2 minutes for all vehicle systems to power down.
    • S13 door lock switch - RHD
    • S126 driver mode select switch - LHD
  2. Test for less than 15 Ω between the ground circuit terminal 4 and ground.
    • If 15 Ω or greater 
    1. Vehicle 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.
    • If less than 15 Ω 
  3. Connect a test lamp between the control circuit terminal 3 and ground, vehicle in Service Mode, park lamps ON.
  4. Verify the test lamp changes from LOW to HIGH as the dimmer switch is activated from LOW to HIGH.
    • If the test lamp is always OFF 
    1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC controls.
    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 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 A20 radio/HVAC controls.
    • If the test lamp is always ON full intensity 
    1. Vehicle OFF, disconnect the harness connector at the A20 radio/HVAC controls, vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the A20 radio/HVAC controls.
    • If the test lamp changes from LOW to HIGH 
  5. Test or replace the appropriate switch.

Park Assist Switch Amber LED Backlighting Malfunction

  1. Vehicle OFF, disconnect the harness connector at the S48B multifunction switch - overhead console.
  2. Connect a test lamp between the control circuit terminal 3 and ground.
  3. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Vehicle OFF, 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.
      • 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 K9 body control module.
    • If the test lamp is always ON 
    1. Vehicle OFF, disconnect the X1 harness connector at the K9 body control module, vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminal and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K9 body control module.
    • If the test lamp turns ON and OFF 
  4. Vehicle OFF.
  5. Connect a test lamp between the control circuit terminal 3 and low reference circuit terminal 6.
  6. Verify the test lamp turns ON and OFF when commanding the LED Backlight Dimming ON and OFF with a scan tool.
    • If the test lamp is always OFF 
    1. Vehicle OFF, disconnect the X1 harness connector at the K41 front and rear parking assist control module, vehicle in Service Mode.
    2. Test for less than 1 V between the low reference circuit terminal 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 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 K41 front and rear parking assist control module.
    • If the test lamp turns ON and OFF 
  7. Test or replace the S48B multifunction switch - overhead console.

Passenger Air Bag Disable Indicator Backlighting Malfunction

  1. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the P14 passenger air bag disable indicator. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the ground circuit terminal 2 and ground.
    • If 5 Ω or greater 
    1. Vehicle 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.
    • If less than 5 Ω 
  3. Connect a test lamp between the control circuit terminal 4 and ground, vehicle in Service Mode.
  4. Verify the test lamp turns ON and OFF while turning the vehicle mode switch between Service Mode and Vehicle OFF.
    • If the test lamp is always OFF 
    1. Vehicle OFF, disconnect the X1 harness connectors 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.
      • 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 X50A fuse block - underhood.
    • If the test lamp is always ON 
    1. Vehicle OFF, remove the F54UA at the X50A fuse block - underhood, vehicle in Service Mode.
    2. Test for less than 1 V between the control circuit terminal 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 test lamp turns ON and OFF 
  5. Test or replace the P14 passenger air bag disable indicator.
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