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Circuit/System Testing

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

Dimmer Switch - Malfunction

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: @ S30 Headlamp Switch
  3. Ignition - On / Vehicle - In Service Mode
  4. Test for battery voltage between the test points:Circuit terminal 12 & Ground
    • If less than battery voltage 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X1 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Circuit terminal 12 @ S30 Headlamp Switch & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    4. Test for less than 2 ohms between the test points:Circuit terminal 12 @ S30 Headlamp Switch & Circuit terminal 13 X1 @ K9 Body Control Module
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If battery voltage 
  5. Verify a test lamp does not turn On between the test points:B+ & Signal circuit terminal 11 @ S30 Headlamp Switch
    • If the test lamp turns On 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X2 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Signal circuit terminal 11 & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component:K9 Body Control Module
      • Go to next step: If the test lamp does not turn On 
  6. Test for battery voltage between the test points:S30 Headlamp Switch - Circuit terminal 12 & Signal circuit terminal 11
    • If less than battery voltage 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X2 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Signal circuit terminal 11 @ S30 Headlamp Switch & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Test for less than 2 ohms between the test points:Signal circuit terminal 11 @ S30 Headlamp Switch & Signal circuit terminal 9 X2 @ K9 Body Control Module
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
      • Go to next step: If battery voltage 
  7. Test for battery voltage between the test points:S30 Headlamp Switch - Circuit terminal 12 & Low Reference circuit terminal 7
    • If less than battery voltage 
  8. Ignition/Vehicle - Off
  9. Disconnect the electrical connector:X1 @ K9 Body Control Module
  10. Ignition - On / Vehicle - In Service Mode
  11. Test for less than 1 V between the test points:Low Reference circuit terminal 7 & Ground
    • If 1 V or greater - Repair the short to voltage on the circuit.
    • Go to next step: If less than 1 V
  12. Test for less than 2 ohms between the test points:Low Reference circuit terminal 7 @ S30 Headlamp Switch & Low Reference circuit terminal 7 X1 @ K9 Body Control Module
    • If 2 ohms or greater - Repair the open/high resistance in the circuit.
    • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If battery voltage 
  13. Verify a test lamp does not turn On between the test points:Circuit terminal 12 @ S30 Headlamp Switch & Ground
    • If the test lamp turns On 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector:X1 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Circuit terminal 12 @ S30 Headlamp Switch & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V - Replace the component:K9 Body Control Module
      • Go to next step: If the test lamp does not turn On 
  14. Test or replace the component:S30 Headlamp Switch

Backlight Dimming - Malfunction

    NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the appropriate component:
  3. Test for less than 15 ohms between the test points:Ground circuit terminal @ Component harness & Ground
    • If 15 ohms or greater 
    1. Ignition/Vehicle - Off
    2. Test for less than 2 ohms between the test points:Ground circuit terminal @ Component harness & Ground terminal
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 15 ohms 
  4. Connect a test lamp between the test points:Control circuit terminal @ Component harness & Ground
  5. Ignition - On / Vehicle - In Service Mode
  6. Scan Tool Device Control - Amber - LED Backlight Dimming = On and Off
  7. Verify the test lamp turns On and Off.
    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the appropriate electrical connector:
      • X2 @ K9 Body Control Module
      • X7 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Control circuit terminal & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    4. Test for less than 2 ohms between the test points:Control circuit terminal @ Component harness & The other end of the circuit
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If the test lamp is always On 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector:
      • X2 @ K9 Body Control Module
      • X7 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Control circuit terminal @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component:K9 Body Control Module
    • Go to next step: If the test lamp turns On and Off 
  8. Replace the appropriate component:

LED Backlight Dimming - Malfunction

  1. Ignition/Vehicle - Off
  2. Disconnect the appropriate component:
    • A98 Front Overhead Console Assembly
    • S126 Drive Mode Select Switch { With UFQ }
    • S13D Door Lock Switch - Driver
    • S13P Door Lock Switch - Passenger
    • S48E Multifunction Switch - Center Console
  3. Ignition - On / Vehicle - In Service Mode
  4. Backlight Dimming Switch - High Power
  5. Verify a test lamp turns On between the test points:
    • A98 Front Overhead Console AssemblyTerminal 18 & Ground
    • S126 Drive Mode Select SwitchTerminal 6 & Ground { With UFQ }
    • S13D Door Lock Switch - DriverTerminal 5 & Ground
    • S13P Door Lock Switch - PassengerTerminal 5 & Ground
    • S48E Multifunction Switch - Center ConsoleTerminal 3 & Ground
    • If the test lamp is always Off 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector:X1 @ K9 Body Control Module
    3. Test for infinite resistance between the test points:Control circuit terminal @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    4. Test for less than 2 ohms between the test points:Control circuit terminal @ Component harness & The other end of the circuit
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component:K9 Body Control Module
    • Go to next step: If the test lamp is always On 
  6. Backlight Dimming Switch - Low Power Mode
  7. Verify the test lamp turns On and changes intensity.
    • A98 Front Overhead Console Assembly Terminal 18 & Ground
    • S126 Drive Mode Select Switch Terminal 6 & Ground { With UFQ }
    • S13D Door Lock Switch - Driver Terminal 5 & Ground
    • S13P Door Lock Switch - Passenger Terminal 5 & Ground
    • S48E Multifunction Switch - Center Console Terminal 3 & Ground
    • If the test lamp turns On but does not change intensity 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the electrical connector:X1 @ K9 Body Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points:Control circuit terminal @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component:K9 Body Control Module
    • Go to next step: If the test lamp turns On and changes intensity 
  8. Replace the appropriate component:
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