The vehicle immobilizer system consists of the ECM, the SMARTRA3 and ignition keys with built-in transponder.
The ECM carries out the check of ignition key by special encryption algorithm with SMARTRA3 and Transponder.
The encryption algorithm (between ECM ans SMARTRA3) is used one offered from BOSCH.
The encryption algorithm (between ECM and Transponder) is Hitag2 type which is the high level.
When IGN On, the ECM executes the key Authentication after SMARTRA3 authentication. The Engine can be started in case of the success in SMARTRA3 and key authentication.
The Key teaching procedure starts with ECM request of PIN from Scanner. The "virgin“ECM stores the PIN and the key Learning can be started. The "learnt“ECM 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 ECM. If the SMARTRA3 status is learnt and PIN number is different, the SMARTRA3 will return the incorrect PIN data to the ECM. In this case, The ECM can’t excute the key learning process.
The ECM sets DTC P1696 if transponder key that can’t be register(TP not in the password mode or whose transport data has been changed) is inserted for registration procedure.
Item
Detecting Condition
Possible Cause
DTC Strategy
-
Invalid transponder
Enable Conditions
IG ON
Threshold value
Virgin TP at PCM/ECM status “Learnt”
Learnt(Invalid) TP at PCM/ECM status “Learnt”
Detecting time
Immediately
FAIL SAFE