Immobilizer Control Module

The immobilizer control module mounts to the steering column. The immobilizer control module contains an antenna arranged in a ring around the ignition lock cylinder. The transponder enters the very limited reading range (2-3 cm) of the antenna with the ignition in the RUN position when the transponder key inserts in the ignition lock cylinder. This guarantees that only the key that is inserted in the ignition lock cylinder can have its transponder code audited. This excludes the possibility of interference from other transponder keys in the vicinity. The immobilizer control module makes no determination as to the validity of the transponder key while the immobilizer control module receives the signal from the transponder key. This is done solely by the ECM. The ECM performs all decision making processes. Therefore, any theft attempt by hot-wiring the immobilizer control module or any wiring harness will not result in a successful bypass of the system. The immobilizer control module cannot be disassembled. Additionally, the immobilizer control module must be serviced as an assembly.