The remote function actuator (RFA) module performs the functions of interpreting the signals from the transmitters and relaying the information to other modules via class 2 serial data. The RFA module does not directly control any functions. The RFA module is able to differentiate between the various transmitters and must be programmed in order to accept signals from all transmitters if one or both transmitters are to be replaced or if spares are added.

The transmitter is a battery powered, water resistant, radio frequency signal generator. Each transmitter is uniquely recognized by the remote function actuator (RFA) module. The RFA module is capable of recognizing up to 4 transmitters. Replacement or spare transmitters for the vehicle may be obtained. The RFA module must be reprogrammed in order to accept the new transmitter.

This system allows 1 transmitter to be matched to as many different factory equipped RFA Cadillacs as the owner chooses. In order to program several cars to 1 transmitter, follow the reprogramming procedure for each of the vehicles using the desired same transmitter. Each vehicle has 2  transmitters labeled transmitter #1 and transmitter #2. Each transmitter is recognized individually by the RFA module and sets programmable features to the correct setting for each transmitter.

The keyless entry system uses a system called rolling code. When the transmitter and the remote function actuator (RFA) module are initially programmed, a code is established that is unique to the transmitter and the RFA module. Each time thereafter when the transmitter is used, within range of the RFA module, a new code is used.

When the transmitter goes out of synchronization with the RFA module and you have to re-synchronize the transmitter, the RFA module recognizes the transmitter as a programmed transmitter and establishes a new code sequence with the transmitter. Each transmitter that is programmed to the RFA module has unique identification.