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Home >> Cadillac >> 2007 >> STS V >> Repair and Diagnosis >> Body & Frame >> Door Locks >> Keyless Entry System And Remote Functions >> Diagnostic Information and Procedures >> DTC B3123 >> Circuit Description

Circuit Description

The headliner and console antennas are located in the rear headliner area and in the center console. They are used as a short range low frequency (LF) antennas. The headliner and console antennas are used to determine transmitter placement within the vehicle. When a valid keyless entry transmitter is within the passenger compartment, the headliner and console antennas broadcast a challenge within the passenger compartment to the transmitter. If the response from the transmitter via radio frequency (RF) is a valid response, the antenna will determine there is a fob within the vehicle. If no response is received, the antenna determines that no fob is in the vehicle.

The headliner and console antennas share a driver within the remote control door lock receiver (RCDLR) and are wired in parallel. The RCDLR has no way to determine which antenna is receiving a valid response from a transmitter, only that a valid response is being received.