Learning Procedures

Key Learning Procedure. Key learning must be performed after replacing a faulty PCM (ECM) module, or when providing additional keys to the vehicle owner. The procedure begins with the PCM (ECM) requesting vehicle-specific data (PIN code: 6 digits) from the tester. A "new" PCM (ECM) can be started with the vehicle-specific data and key learning. The "learned" PCM (ECM) compares the vehicle-specific data from the tester with the stored data. If the data is correct, learning can continue. If incorrect vehicle data is sent to the PCM (ECM) three times, the PCM (ECM) will reject the key learning request for one hour. This time cannot be shortened by disconnecting the battery or any other manipulation. After the battery is reconnected, the timer starts again for one hour. Key learning is performed by turning the ignition ON with the key and an additional tester command. The PCM (ECM) stores the relevant data in EEPROM and in the transponder. The PCM (ECM) then performs the required authentication to confirm the learning process. Successful programming is then confirmed by a message to the tester. If the key is already known to the PCM (ECM) from a previous learning, authentication is accepted and the EEPROM data is updated. The transponder content is not changed (this is not possible for a learned transponder). An attempt to re-learn a key that has already been learned during the same learning cycle is recognized by the PCM (ECM). It rejects the key, and a message is sent to the tester. The PCM (ECM) rejects invalid keys presented for learning. A message is sent to the tester. A key may be invalid due to transponder errors or other causes resulting from unsuccessful data programming. If the PCM (ECM) detects different transponder and PCM (ECM) authenticators, the key is considered invalid. The maximum number of learnable keys is 8. If an error occurs during the immobilizer service menu, the engine control module (ECM) status remains unchanged and the specified DTC is stored. If the PCM (ECM) status and key status do not match for key learning, the tester procedure will be stopped, and the specified DTC will be stored in the PCM (ECM).

1. PCM (ECM) teaching status.

   

   

   

   

   

   

   

   

   

   

   

2. PCM (ECM) Virgin Status. After replacing with a new PCM (ECM), the diagnostic tester shows that the PCM (ECM) is in the initial state of key learning mode. The "VIRGIN" status means that the PCM (ECM) does not match any PIN code yet.

User Password Learning Procedure. The user password for Limp Home is learned at a service station. The vehicle owner can select a four-digit number. The user password learning is accepted only by a "learned" PCM (ECM). Before the user password is first entered into the PCM (ECM), the password status is "virgin". The Limp Home function is not available. Learning starts when the ignition is turned on with a valid key (learned key) and the user password is sent by the tester. After successful learning, the user password status changes from "virgin" to "learned". The learned user password can also be changed. This can be done if the user password status is "learned" and the tester sends access authorization, either the old user password or the vehicle data. After correct authorization, the PCM (ECM) requests a new user password. The status remains "learned", and the new user password will be valid for the next Limp Home mode. If incorrect user passwords or incorrect vehicle data are sent to the PCM (ECM) three times in a row or with interruptions, the PCM (ECM) will reject the password change request for one hour. This time cannot be shortened by disconnecting the battery or by any other action. After the battery is reconnected, the timer starts again for one hour.

User Password Learning

※ If an incorrect password is entered, repeat the procedure from the first step after 10 seconds.

Changing the User Password