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. There are two types of immobilizer. One is a "SMARTRA (SMART TRansponder Antenna)" type and another is a "shinchang" type.
1.
Break
A.
The "SMARTRA" type immobilizer system is applied to the D2.0 engine and 2.0β engine.
B.
The SMARTRA system consists of a transponder located in the ignition key, a coil antenna, a SMARTRA unit, an indicator light and the ECM.
C.
The SMARTRA communicates to the 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.
D.
When the key is inserted in the ignition and turned to the ON position, the coil antenna sends power to the transponder in the ignition key. The transponder then sends a coded signal back through the SMARTRA unit to the ECM.
E.
If the proper key has been used, the 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.
F.
If the wrong key has been used and the code was not received or recognized by the ECM the indicator light will continue blinking for about five seconds until the ignition switch is turned OFF.
G.
If it is necessary to rewrite the ECM to learn a new key, the dealer needs the customer's vehicle, all its keys and the Hi-scan (pro) equipped with an immobilizer program card. Any key that is not learned during rewriting will no longer start the engine.
H.
The immobilizer system can store up to four key codes.
I.
If the customer has lost his key, and cannot start the engine, contact HMC motor service station.
2.
Shinchang type immobilizer
A.
The " Shinchang " type immobilizer system is applied to the 2.7δ engine.
B.
The shinchang system consists of a transponder located in the ignition key, a coil antenna, an ICM (Immobilizer control module) , an indicator light and the ECM.
C.
When the key is inserted in the ignition and turned to the ON position, the coil antenna sends power to the transponder in the ignition key. The transponder then sends a coded signal back through the coil antenna to the ICM.
D.
If the ID code transmitted from the key does not match the pre-registered code in the ICM, injection is not performed by the engine ECM. Hence, each vehicle has a set of keys containing a unique ID code which are registered on the ICM. This signal is captured by the coil antenna located in the front section of the steering handle lock and transmitted to the ICM. The ICM analyses and verifies the signal to determine if the signal matches the pre-registered code.If the signal is verified, the ICM transmits a message to the engine ECM to allow injection. The immobilizer indicator light in the cluster will simultaneously come on for more than five seconds, indicating that the ICM has recognized the code sent by the transponder.If the signal is not verified by the ICM, fuel injection is not performed by the engine ECM. The indicator light will continue blinking for five seconds until the ignition switch is turned OFF.Communication between ICM and ECM communicates through the K-line of ECM. K-line is also used for the communication between ECM and scan tool. there is a regal inside of ICM to switch the communication.
E.
If it is necessary to rewrite the ICM to learn a new key, the dealer needs the customer's vehicle, all its keys and the Hi-scan (pro) equipped with an immobilizer program card. Any key that is not learned during rewriting will no longer start the engine.
F.
The immobilizer system can store up to four key codes.
G.
If the customer has lost his key, and cannot start the engine, contact HMC motor service station.
OPERATION
ECM (Engine Control Module)
1.
SMARTRA type immobilizer
The ECM carries out a check of the ignition key using a special encryption algorithm, which is programmed into the transponder as well as the ECM simultaneously. Only if the results are equal, the engine can be started. The data of all transponders, which are valid for the vehicle, are stored in the ECM.
2.
Shinchang type immobilizer
In the Ignition ON position, the engine ECM receives information from the ICM and permits injection to take place.
ICM (Immobilizer Control Module)
The ICM carries out communication with the built-in transponder in the ignition key. This wireless communication runs on RF (Radio frequency of 125 kHz). The ICM is mounted at the behind of the crush pad under panel close to the antenna coil for RF transmission and receiving.
The ICM carries out a check of the ignition key using a special encryption algorithm, which is programmed into the transponder as well as the ICM simultaneously. Only if the results are equal, transmits the signal to the ECM to permits injection. The data of all transponders, which are valid for the vehicle, are stored in the ICM.
SMARTRA unit
The SMARTRA carries out communication with the built-in transponder in the ignition key. This wireless communication runs on RF (Radio frequency of 125 kHz). The SMARTRA is mounted at the behind of the crush pad under panel close to the antenna coil for RF transmission and receiving. The RF signal from the transponder, received by the antenna coil, is converted into messages for serial communication by the SMARTRA device. And, the received messages from the ECM are converted into an RF signal, which is transmitted to the transponder by the antenna.
The SMARTRA does not carry out the validity check of the transponder or the calculation of encryption algorithm. This device is only an advanced interface, which converts the RF data flow of the transponder into serial communication to the ECM and vice versa.
TRANSPONDER (Built-in keys)
The transponder has an advanced encryption algorithm. During the key teaching procedure, the transponder will be programmed with vehicle specific data. The vehicle specific data are written into the transponder memory. The write procedure is once only; therefore, the contents of the transponder can never be modified or changed.
