Immobilizer Control System: Components
COMPONENT DESCRIPTION CHART
| COMPONENT | DESCRIPTION |
|---|---|
| TRANSPONDER (Built-in keys) | When ignition is ON, the coil supplies energy to the transponder, which in turn accumulates energy in the condenser. Once the energy supplied from the coil has stopped, using the stored energy in the condenser, the transponder transmits the secret data. 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. |
| COIL ANTENNA | Supplies energy to the transponder. Receives signal from the transponder. Sends transponder signal to the BCM. |
| BODY CONTROL MODULE (BCM) | The BCM carries out communication with the built - in transponder in the ignition key. This wireless communication runs on RF (Radio Frequency) . The RF signal from the transponder, received by the antenna coil, is converted into messages for serial communication by the BCM. And, the received messages from the ECM are converted into an RF signal, which is transmitted to the transponder by the antenna. In case of "SMARTRA" type immobilizer system the BCM 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. |
| ENGINE CONTROL MODULE (ECM) | In case of "SMARTRA" type immobilizer system 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 can the engine be started. The data of all transponders, which are valid for the vehicle, are stored in the ECM. |
| DATA LINK CONNECTOR (DLC) | By connecting the voltmeter or Hi-scan, the control module diagnostic code can be read. |
| DIAGNOSTIC TESTER | Has the function BCM, ECM, and key diagnosis and change. |