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Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis >> Body & Frame >> Ignition Switch/Steering Lock >> Immobilizer System >> Diagnostic Information and Procedures >> DTC P1649: Immobilizer Security Code Not Programmed >> Circuit/System Verification
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Circuit/System Verification

  1. Verify there are no immobilizer DTCs set in the K9 Body Control Module.
    • If no immobilizer DTCs are set in the K9 Body Control Module 
  2. Perform the K20 Engine Control Module immobilizer learn using the engine control module IMMO Learn in SPS. Refer to Immobilizer System Component Programming .
  3. Verify the engine starts after the K20 Engine Control Module completes the learn procedure.
    • If the engine does not start 

      Replace the K20 Engine Control Module.

    • If the engine starts 
  4. All OK.
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