Immobilization System: Transponder

A transponder, consisting of a wireless Electronic Erasable Programmable Read Only Memory (EEPROM), is incorporated into the head of each ignition key, including the 'wallet' ignition key. A password and key code in the transponder provides each ignition key with a unique identification. As a further security measure, the transponder contains a rolling code number written to it from the immobilization ECU. The transponder key code and rolling code are entirely separate from the remote handset codes.

The transponder is written to and read from by the immobilization ECU via the transponder coil. The maximum range for communication between the transponder and the transponder coil is approximately 20 mm (0.8 in).