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Home >> GMC >> 2018 >> Terrain SL >> Repair and Diagnosis (Single Page) >> Body & Frame >> Ignition Switch/Steering Lock >> Immobilizer System >> Diagnostic Information And Procedures >> DTC B2955: Security Sensor Data Circuit >> Circuit/System Testing
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Circuit/System Testing

  1. Verify DTC B2955 did not set immediately after the replacement or programming of the K9 Body Control Module or after performing the Immobilizer System Component Programming procedure.
    • If the DTC set immediately after the replace or programming of the K9 Body Control Module or after performing the Immobilizer System Component Programming procedure. 

      Perform the Immobilizer System Component Programming  procedure using a new vehicle key. After the new key has been learned, the existing vehicle keys may be learned to the vehicle.

    • Go to next step: If the DTC did not set immediately after the replace or programming of the K9 Body Control Module or after performing the Immobilizer System Component Programming procedure. 
  2. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the K89 Immobilizer Control Module. It may take up to 2 min for all vehicle systems to power down.
  3. Verify a test lamp illuminates between the low reference circuit terminal 1 and B+.
    • If the test lamp does not illuminate 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. 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.
    • Go to next step: If the test lamp illuminates 
  4. Ignition ON.
    5. NOTE:

    In some instances, the K9 Body Control Module may only apply voltage for 3 s immediately after the ignition is turned ON. It may be necessary to monitor the DMM while turning the ignition ON to observe the voltage.

  5. Test for greater than 9 V between the B+ circuit terminal 3 and ground.
    • If 9 V or less 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the B+ 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+ 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.
    • Go to next step: If greater than 9 V 
  6. Test for greater than 4 V between the serial data circuit terminal 2 and ground.
    • If 4 V or less 
    1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
    2. Test for infinite resistance between the serial data 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 serial data 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.
    • Go to next step: If greater than 4 V 
  7. Ignition OFF, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
  8. Test for less than 1 V between the K89 Immobilizer Control Module serial data circuit terminal 2 and ground.
    • If 1 V or greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  9. Replace the K89 Immobilizer Control Module.
  10. Verify DTC B2955 does not set while operating the vehicle under the conditions for running the DTC.
    • If DTC B2955 is set 

      Replace the K9 Body Control Module.

    • Go to next step: If DTC B2955 is not set 
  11. All OK.
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