LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2017 >> CT6 Plug-In >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Entertainment Systems >> Cellular System, Entertainment System And Navigation System - Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> Bluetooth Malfunction >> Circuit/System Verification
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Verification

  1. Verify no DTCs are present.
    • If no DTCs are present 
  2. Verify the K74 Human Machine Interface Control Module calibrations are current.
    • If the K74 Human Machine Interface Control Module calibrations are not current 

      Reprogram the K74 Human Machine Interface Control Module and re-evaluate the concern.

    • If no update calibrations are available 
  3. Ignition On/Vehicle in Service Mode. Infotainment system ON.
    NOTE: The MIT tool can be used to test either cellular phone or streaming audio functions. Refer to the tool instructions and perform the appropriate test(s) related to the customers concern in the following steps.
  4. Verify the infotainment system successfully pairs with the MIT tool.
    • If the infotainment system does not successfully pair with the MIT tool. 

      Replace the K74 Human Machine Interface Control Module.

    • If the infotainment system successfully pairs with the MIT tool. 
  5. Verify the infotainment system successfully completes the desired feature test using the MIT tool.
    • If the feature test is not successful 

      Replace the K74 Human Machine Interface Control Module.

    • If the feature test is successful 
  6. All OK. Refer to Diagnostic Aids .