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Circuit/System Testing

WARNING: This page is about a different car, the 2018 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the X1 harness connector at the K74 Human Machine Interface Control Module.
  2. Disconnect the X1 harness connector at the K31 Navigation Control Module. Ignition ON.
  3. Test for less than 1 V between the signal circuit terminal listed below and ground.
    • Voice recognition audio signal terminal 10
    • Voice recognition audio low reference terminal 9
    • If 1 V greater 

      Repair the short to voltage on the circuit.

    • Go to next step: If less than 1 V 
  4. Ignition OFF.
  5. Test for infinite resistance between the signal circuits listed below and ground:
    • Voice recognition audio signal terminal 10
    • Voice recognition audio low reference terminal 9
    • If less than infinite resistance 

      Repair the short to ground on the circuit.

    • Go to next step: If infinite resistance 
  6. Test for less than 5 Ω between the terminals listed below:
    • K74 Human Machine Interface Control Module signal circuit terminal 1 X1 and the K31 Navigation Control Module signal circuit terminal 10 X1
    • K74 Human Machine Interface Control Module low reference circuit terminal 2 X1 and the K31 Navigation Control Module low reference circuit terminal 9 X1
    • If 5 Ω greater 

      Repair the open/high resistance in the circuit.

    • Go to next step: If less than 5 Ω 
  7. Replace the K74 Human Machine Interface Control Module. Connect all harness connectors.
    8. NOTE:

    Refer to the Owner's Manual and/or the Navigation System Owner's Manual for voice recognition use and commands.

  8. Begin voice recognition for the infotainment system and clearly speak one of the available commands.
  9. Verify the infotainment system responds correctly to the command.
    • If the infotainment system does not respond correctly to the command 
    1. Clearly speak a different command.
    2. Verify the infotainment system responds correctly to the command.
      • If the infotainment system does not respond correctly to any commands 

        Replace the K31 Navigation Control Module.

    • Go to next step: If the infotainment system responds correctly to the command 
  10. All OK
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