Hyundai Elantra MD/UD: Description - Description and Operation - Immobilizer System - Body Electrical System - Hyundai Elantra MD 2010-2015 Service manualHyundai Elantra MD/UD: Description

The immobilizer system will disable the vehicle unless the proper ignition key is used. In addition to the currently available anti-theft systems such as car alarms, the immobilizer system aims to drastically reduce the rate of auto theft.
1.
Encrypted SMARTRA type immobilizer
A.
The SMARTRA system consists of a passive challenge - response (mutual authentication)transponder located in the ignition key, an antenna coil, a encoded SMARTRA unit, an indicator light and the PCM(ECM).
B.
The SMARTRA communicates to the PCM(ECM) (Engine Control Module) via a dedicated communications line. Since the vehicle engine management system is able to control engine mobilization, it is the most suitable unit to control the SMARTRA.
C.
When the key is inserted in the ignition and turned to the ON position, the antenna coil sends power to the transponder in the ignition key. The transponder then sends a coded signal back through the SMARTRA unit to the PCM(ECM).
D.
If the proper key has been used, the PCM(ECM) will energize the fuel supply system. The immobilizer indicator light in the cluster will simultaneously come on for more than five seconds, indicating that the SMARTRA unit has recognized the code sent by the transponder.
E.
If the wrong key has been used and the code was not received or recognized by the PCM(ECM) the indicator light will continue blinking for about five seconds until the ignition switch is turned OFF.
F.
If it is necessary to rewrite the PCM(ECM) to learn a new key, the dealer needs the customer's vehicle, all its keys and the GDS equipped with an immobilizer program card. Any key that is not learned during rewriting will no longer start the engine.
G.
The immobilizer system can store up to eight key codes.
H.
If the customer has lost his key, and cannot start the engine, contact Hyundai motor service station.

Components Operations
PCM (Power Train Control Module) 1. The PCM(ECM) (A) carries out a check of the ignition key using a special encryption algorithm, which is programmed into the transpo ...