Programming and Relearning
TEACHING PROCEDURES1. Key Teaching Procedure.
1. Learnt Status.
2. Virgin Status.
After Replacing new "ECM" scantool displays that ECM is Virgin status in Key Teaching mode "VIRGIN" status means that ECM has not matched any PIN Code before.
NOTE:
Key Teaching Procedure
Key teaching must be done after replacing a faulty ECM or when providing additional keys to the vehicle owner. The procedure starts with an ECM request for vehicle specific data from the scanner. The "virgin" ECM stores the vehicle specific data and the key teaching can be started. The "learnt" ECM compares the vehicle specific data from the scanner with the stored data. If the data are correct, the teaching can proceed.
If incorrect vehicle specific data have been sent to the ECM three times, the ECM will reject the request of key teaching for one hour. This time cannot be reduced by disconnecting the battery or any other manipulation. After reconnecting the battery, the timer starts again for one hour.
The key teaching is done by ignition on with the key and additional tester commands. The ECM stores the relevant data in the EEPROM and in the transponder. Then the ECM runs the authentication required for confirmation of the teaching process. The successful programming is then confirmed by a message to the scanner. If the key is already known to the ECM from a previous teaching, the authentication will be accepted and the EEPROM data are updated.
There is no changed transponder content (this is impossible for a learnt transponder).
The attempt to repeatedly teach a key, which has been taught already during the same teaching cycle, is recognized by the ECM. This rejects the key and a message is sent to the scanner.
The ECM rejects invalid keys, which are presented for teaching. A message is sent to the scanner.
The key can be invalid due to faults in the transponder or other reasons, which result from unsuccessful programming of data. If the ECM detects different authenticators of a transponder and an ECM, the key is considered to be invalid. The maximum number of taught keys is 4.
If an error occurs during the Immobilizer Service Menu, the ECM status remains unchanged and a specific fault code is stored. If the ECM status and the key status do not match for teaching of keys, the scanner procedure will be stopped and a specific fault code will be stored at ECM.
2. ECM Neutralization
This function is for neutralizing the ECM and Key.
ex) When lost key, Neutralize the ECM then teach keys. (Refer to the Things to do when Key & PIN Code The ECM can be set to the "neutral" status by a scanner. A valid ignition key is inserted and after ignition on is recorded, the ECM requests the vehicle specific data from the scanner. The communication messages are described at "Neutral Mode". After successfully receiving the data, the ECM is neutralized.
The ECM remains locked. Neither the limp home mode nor the "twice ignition on" function is accepted by ECM.
The teaching of keys follows the procedure described for virgin ECM. The vehicle specific data have to be unchanged due to the unique programming of transponder. If data should be changed, new keys with virgin transponder are requested.
3. Password Teaching / Changing
The user password is used only for limp home function. The user password for limp home is taught at the service station. The owner of the vehicle can select a number with four digits. User password teaching is only accepted by a "learnt" ECM. Before first teaching of user password to an ECM, The status of the password is "virgin". No limp home function is possible. The teaching is started by ignition on, with a valid key and sending the user password by scanner. After successful teaching, the status of the user password changes from "virgin" to "learnt". The learnt user password can also be changed. This can be done if the user password status is "learnt" and the scanner sends authorization of access, either the old user password or the vehicle specific data. After correct authorization, the ECM requests the new user password. The status remains "learnt" and the new user password will be valid for the next limp home mode. If incorrect user passwords or wrong vehicle specific data have been sent to the ECM three times, the ECM will reject the request to change the password for one hour. This time can not be reduced by disconnecting the battery or any other actions. After reconnecting the battery, the timer starts again for one hour.
The user password can be in status.
00. Not yet checked.
The status is stored in the EEPROM. In case of incorrect or no plausible data from this circuit, the ECM can not check the status and the ECM sends Not yet checked.
01. Learnt
The password has been taught successfully to the ECM.
02. Virgin
This is the status at the end of the ECM production line before delivery to the final customer.
04. Locked by timer
After a certain number of incorrect inputs, the ECM is locked for one hour and no inputs are accepted during this time.
05. Teaching not accepted
This status is set, for example, if the ECM is in neutral status.