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Home >> Cadillac >> 2007 >> CTS V >> Repair and Diagnosis >> External Pages >> Different car >> Section 816 (Keyless Entry System And Remote Functions) >> Diagnostic Information and Procedures >> DTC B3123 >> Circuit/System Testing
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Circuit/System Testing

WARNING: This page is about a different car, the 2013 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the harness connector at the console passive antenna.
  2. Place a valid keyless entry transmitter in the pocket located in the center console. This will allow the console active antenna to authenticate the keyless entry transmitter and allow the ignition to be turned on.
  3. Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal A and ground.
    • If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RCDLR.
  4. Connect a DMM, set to capture AC voltage using the MIN MAX function, between the signal circuit terminal A and the low reference circuit terminal B.
  5. Attempt to start the vehicle. Verify the DMM captured an AC voltage signal.
    • If an AC voltage was not captured, test the signal circuit and the low reference circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the RCDLR.
  6. If all circuits test normal, test or replace the console passive antenna.
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