The vehicle immobilizer system consists of the PCM, the SMARTRA3 and ignition keys with built-in transponder.
The PCM carries out the check of ignition key by special encryption algorithm with SMARTRA3 and Transponder.
The encryption algorithm (between PCM and SMARTRA3) is the one offered from BOSCH.
The encryption algorithm (between PCM and Transponder) is Hitag type 2 which is a high level system. With IGN On, the PCM executes the key Authentication after SMARTRA3 authentication. The Engine can be started when the key authentication is confirmed by the SMARTRA3.
The Key teaching procedure starts with PCM request of PIN from Scanner. The "virgin" PCM stores the PIN and the key Learning can be started. The "learnt" PCM compares the PIN from tester with the vehicle password in Transponder. If the data are correct, the key Learning can be started.
Scanner requests the Learning of the first key, the SMARTRA3 is registered at first and then the first key is registered by PCM. If the SMARTRA3 status is learnt and PIN number is different, the SMARTRA3 will return the incorrect PIN data to the PCM. In this case, The PCM can’t excute the key learning process.
The PCM sets DTC P1675 if characteristic data of transponder doesn't coincide with that of PCM owing to transponder programming error
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
- | 1. Invalid transponder. ※ Invalid characteristic data ※ No transponder or more than two transponder is detected by coil antenna |
Enable Conditions |
•
IG ON(During the authentification) | |
Threshold value |
•
Invalid characteristic data
•
No transponder or more than two transponder is detected by coil antenna | |
Detecting time |
•
Immediately | |
Fail Safe |
•
- |
Fig.1) A normal signal waveform of antenna and immobilizer communication when IG key(TP : Transponder) is OFF to ON.
