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Home >> Cadillac >> 2020 >> CT6 V >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel And Console Trim >> Diagnostic Information And Procedures >> Instrument Panel Compartment Door Latch Release Malfunction >> Circuit/System Testing

Circuit/System Testing

  1. Ignition/Vehicle Off and all vehicle systems Off. Disconnect the harness connector at the M91 Instrument Panel Compartment Door Unlatch Actuator. It may take up to 2 minutes 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. Ignition/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.
    • Go to next step: If less than 10 Ω 
  3. Ignition On/Vehicle in Service Mode.
  4. Connect a test lamp between the control circuit terminal 1 and ground, Ignition On/Vehicle in Service Mode.
  5. Verify the test lamp does not turn ON and OFF when pressing the appropriate switch on the S48D Multifunction Switch 2 - Instrument Panel
    • If the test lamp turns ON and OFF 

      Test or replace the M91 Instrument Panel Compartment Door Unlatch Actuator.

    • Go to next step: If the test lamp does not turn ON and OFF 
  6. Ignition/Vehicle Off. Connect the harness connector at the M91 Instrument Panel Compartment Door Unlatch Actuator. Disconnect the harness connector at the X51A Fuse Block-Instrument Panel. Ignition On/Vehicle in Service Mode.
  7. Verify the M91 Instrument Panel Compartment Door Unlatch Actuator is not activated.
    • If the M91 Instrument Panel Compartment Door Unlatch Actuator is activated 
    1. Ignition/Vehicle Off. Disconnect the harness connector at the M91 Instrument Panel Compartment Door Unlatch Actuator. Ignition On/Vehicle in Service Mode.
    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, test or replace the M91 Instrument Panel Compartment Door Unlatch Actuator.
    • Go to next step: If the M91 Instrument Panel Compartment Door Unlatch Actuator is not activated 
  8. Connect a 10 A fused jumper wire between the control circuit terminal 7 and B+
  9. Verify the M91 Instrument Panel Compartment Door Unlatch Actuator activates.
    • If the M91 Instrument Panel Compartment Door Unlatch Actuator does not activate 
    1. Ignition/Vehicle Off. Remove the jumper wire, disconnect the harness connector at the M91 Instrument Panel Compartment Door Unlatch Actuator. Ignition On/Vehicle in Service Mode.
    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, test or replace the M91 Instrument Panel Compartment Door Unlatch Actuator.
    • Go to next step: If the M91 Instrument Panel Compartment Door Unlatch Actuator activates 
  10. Ignition/Vehicle Off and all vehicle systems Off. It may take up to 2 minutes for all vehicle systems to power down
  11. Test for less than 10 Ω between the X51A Fuse Block-Instrument Panel ground circuit terminal 6 and ground.
    • If 10 Ω or greater 
    1. Ignition/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.
    • Go to next step: If less than 10 Ω 
  12. Connect the X2 harness connector at the X51A Fuse Block-Instrument Panel. Disconnect the X1 harness connector at the K9 Body Control Module. Ignition On/Vehicle in Service Mode.
  13. Verify the M91 Instrument Panel Compartment Door Unlatch Actuator is not activated.
    • If the M91 Instrument Panel Compartment Door Unlatch Actuator is activated 
    1. Ignition/Vehicle Off. Disconnect the harness connector at the X51A Fuse Block-Instrument Panel.
    2. Test for less than 1 V between the K9 Body Control Module control circuit terminal 6 X1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the X51A Fuse Block-Instrument Panel.
    • Go to next step: If the M91 Instrument Panel Compartment Door Unlatch Actuator is not activated 
  14. Connect a 3 A fused jumper wire between the control circuit terminal 6 and B+
  15. Verify the M91 Instrument Panel Compartment Door Unlatch Actuator activates.
    • If the M91 Instrument Panel Compartment Door Unlatch Actuator does not activate 
    1. Ignition/Vehicle Off. Remove the jumper wire, disconnect the harness connector at the X51A Fuse Block-Instrument Panel. Ignition On/Vehicle in Service Mode.
    2. Test for infinite resistance between the K9 Body Control Module control circuit terminal 6 X1 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 X51A Fuse Block-Instrument Panel.
    • Go to next step: If the M91 Instrument Panel Compartment Door Unlatch Actuator activates 
    16. 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.

  16. Ignition/Vehicle & All vehicle systems - Off
  17. Disconnect the electrical connector: S48D Multifunction Switch 2 - Instrument Panel
  18. Test for less than 10 ohms between the test points: Ground circuit terminal 3 & Ground
    • If 10 ohms or greater 
    1. Ground Connection - Disconnect
    2. Test for less than 2 ohms between the test points: Ground circuit terminal 3 @ Component harness & Ground Connection
      • 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 10 ohms 
  19. Ignition - On / Vehicle - In Service Mode
  20. Momentarily connect a 3 A fused jumper wire between the test points: Signal circuit terminal 12 & Ground

    Verify the component turns On and Off when connecting and disconnecting the jumper wire: M91 Instrument Panel Compartment Door Unlatch Actuator

    • If the component does not turn On and Off 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: 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 12 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step: If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for infinite resistance between the test points: Signal circuit terminal 12 @ Component harness & 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 ohms between the test points: Signal circuit terminal 12 @ Component harness & Terminal 18 X2 @ Control module harness
      • 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 component turns On and Off 
  21. Test or replace the component: S48D Multifunction Switch 2 - Instrument Panel
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