General Information

Component Location





General Description

The immobilizer learning is possible when the status of EMS is "virgin" or "neutral". After comparing vehicle password stored in EMS with vehicle password inputted from scanner, if the result is same, the learnt EMS will start learning the immobilizer system.
The Learning immobilizer system is comprised of the SMARTRA3 learning and the key Learning.
The SMATRA learning is possible in case that the status of SMARTAR is "virgin" or "neutral ". In case that the SMARTRA is "learnt", the SMARTRA3 will transmits the information whether DPN (converted from PIN) inputted from tester is same as the DPN in SMARTRA.
If the EMS receives the key Learning message from scanner, the SMARTRA is registered at first and then, the first key registered by ECM. The SMARTRA is taught in key learning process and stores the DPN (converted from PIN) in memory inside SMARTRA. This DPN (converted from PIN) is used in encryption algorithm between EMS and SMARTRA and to neutralize the SMARTRA. When SMARTRA is neutral, old DPN (converted from PIN) and SEK (generated by DPN) are deleted. New DPN (converted from PIN) can be stored in Neutral SMARTRA. The transponder will be programmed with vehicle specific data. The vehicle specific data are written into the transponder memory. The write procedure is unique; therefore the content of transponder can never be modified or changed. The data are a string of 9 bytes defined by vehicle manufacturer.
The transponder memory is split into two strings called authenticator and key password After this programming the transponder memory is locked and the data (PIN code) cannot be read or changed respectively. The transponder status changes from "virgin" to "learnt". Additionally every transponder includes a unique IDE (Identifier number) of 32 bit. Unique means that the IDE (Identifier number) of all transponder is different from each other. The IDE (Identifier number) is programmed by the transponder manufacturer and is a read-only value. The authenticator and the key password are not transferred from PCM/ECM to transponder or vice versa. Only the results from the encryption algorithm are transferred. It is almost impossible to calculate the vehicle specific data from the encryption result.
For teaching of keys and special purposes the PCM/ECM is connected to the tester device.
When IG is ON, the coil supplies energy to the transponder which in turn accumulates energy in the condenser.
Once the energy supply from the coil has stopped, using the stored energy in the condenser, the transponder transmits the ID CODE (stored within the ASIC).

DTC Description

The ECM sets DTC P1675 if characteristic data of transponder doesn't coincide with that of ECM owing to transponder programming error.

DTC Detecting Condition





Schematic Diagram