The 556UW remote start immobilizer interface module is used when installing remote start products in vehicles equipped with a transponder or RF (Radio Frequency) based immobilizer system. This type of system uses a small chip imbedded in the ignition key, called a transponder, to transmit a very low powered RF signal. This signal is picked up through an antenna (or coil) around the ignition switch which is then sent to the immobilizer’s transceiver. Once the correct signal is received, the immobilizer will enable the ignition and/or fuel systems. If an attempt is made to start the vehicle and the transceiver does not receive a valid code, the ignition and sometimes the fuel systems are disabled. The immobilizer system will then not allow the remote start to successfully start the vehicle. The 556UW bypasses the immobilizer system only while the remote start is in use, maintaining the factory system’s integrity. When the remote start system is not in use the factory immobilizer remains fully functional.