Components and Operation

PCM (Powertrain Control Module)

1. PCM (ECM) (A) verifies the ignition key using a special encryption algorithm that is programmed into both the transponder and the PCM (ECM) simultaneously. The engine can be started only if the results match. The data of all transponders valid for the vehicle is stored in the PCM (ECM). The ERN (encrypted random number) value between the EMS and the encoded SMARTRA unit is verified, and the validity of the encoded key is determined by the EMS.

   

ENCODED SMARTRA unit (A): The SMARTRA communicates with the transponder built into the ignition key. This wireless communication operates at a radio frequency (125 kHz). The SMARTRA is installed behind the cover next to the center crossmember bar. The radio frequency signal from the transponder, received by the antenna coil, is converted into serial communication messages for the SMARTRA. Messages received from the PCM (ECM) are converted into a radio frequency signal, which is transmitted to the transponder through the antenna. The SMARTRA does not perform transponder verification or encryption algorithm calculation. This unit is only an extended interface that converts the transponder's radio frequency data stream into serial communication to the PCM (ECM) and vice versa.

TRANSPONDER (built-in key): The transponder (A) has an advanced encryption algorithm. During the key learning procedure, the transponder is programmed with vehicle-specific data. The vehicle-specific data is written to the transponder memory. This writing procedure is performed only once; therefore, the contents of the transponder can never be modified or changed.

[Key Type]

[Folding Key Type]

Antenna Coil: The antenna coil (A) performs the following functions.

• The antenna coil supplies power to the transponder.
• The antenna coil receives the signal from the transponder.
• The antenna coil sends the transponder signal to SMARTRA. It is located directly in front of the steering column lock.