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Home >> Cadillac >> 2018 >> CT6 Plug-In >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Keyless Entry System And Remote Function >> Diagnostic Information and Procedures >> Keyless Entry System Malfunction (Active) >> Circuit/System Verification
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Circuit/System Verification

  1. Verify that the keyless entry transmitter is correct for the vehicle. This can be accomplished by comparing the part number printed on the transmitter to the appropriate part number in the parts catalog.
    • If the transmitter is incorrect 

      Replace the keyless entry transmitter.

    • Go to next step: If the transmitter is correct 
  2. Ignition OFF, disconnect the remote control door lock receiver coax cable from the K77 Remote Control Door Lock Receiver and from the T23 Radio Antenna Amplifier.
  3. Verify the antenna coax cable passes the coax cable component test. Refer to Component Testing.
    • If the coax cable does not pass the test 

      Replace the antenna coax cable.

    • Go to next step: If the coax cable passes the test 
  4. Connect the antenna coax cable to the K77 Remote Control Door Lock Receiver, ignition ON.
  5. Test for greater than 4.5 V between the antenna coax cable center terminal and ground.
    • If 4.5 V or less 

      Replace the K77 Remote Control Door Lock Receiver.

    • Go to next step: If greater than 4.5 V 
  6. Connect the antenna coax cable to the T23 Radio Antenna Amplifier.
  7. Operate the transmitter while observing the scan tool Key Fob Function parameter for the appropriate transmitter.
  8. Verify the scan tool Key Fob Function parameter corresponds with the function selected on the transmitter.
    • If the Key Fob Function parameter does not correspond with the transmitter selection 
      NOTE:

      Before replacing the transmitter, inspect the transmitter battery contacts for any corrosion or damage. If no corrosion or damage is found, replace the transmitter battery and retest before replacing the transmitter.

    1. Replace the keyless entry transmitter.
    2. Operate the new transmitter while observing the scan tool Key Fob Function parameter for the transmitter.
    3. Verify the scan tool Key Fob Function parameter corresponds with the function selected on the transmitter.
      • If the Key Fob Function parameter does not correspond with the transmitter selection, replace the K77 Remote Control Door Lock Receiver.
      • Go to next step: If the Key Fob Function parameter corresponds with the transmitter selection.
    4. All OK.
    • Go to next step: If the Key Fob Function parameter corresponds with the transmitter selection 
  9. All OK.
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