Password Teaching/Changing
* In case of putting wrong password, retry from first step after 10 seconds.
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.