Limp Home Function

Limp Home Function:

1. By tester
If the ECM detects a fault of SMARTRA or transponder, the ECM will allow limp home function of immobilizer. Limp home is only possible if the user password (4 digits) has been given to the ECM before. This password can be selected by the vehicle owner and is programmed at the service station.

The ECM informs the driver about the limp home condition by blinking the immobilizer indicator. Then the user password can be sent to the ECM via the special tester menu.

Only if the ECM is in status "learnt" and the user password status is "learnt" and the user password is correct will the ECM be unlocked for a period of time (30 sec.). The engine can only be started during this time. After the time has elapsed, engine start is not possible.

If the wrong user password is sent, the ECM will reject the request of limp home for one hour. Disconnecting the battery or other actions cannot reduce this time. After connecting of battery to ECM, the timer starts again for one hour.

2. By ignition key
The limp home can be activated also by the ignition key. The ECM informs the driver by blinking the immobilizer indicator for the limp home condition. Then the user password can be input to ECM can be done by special sequence of ignition on/off.

Only if the ECM is in status "learnt" and the user password status is "learnt" and the user password is correct will the ECM be unlocked for a period of time (30 sec.). The engine can be started during this time. After the time has elapsed, engine start is not possible. After a new password has been input the timer (30 sec.) start again.

After ignition off the ECM is locked (If timer 8 sec. is elapsed). For next start the input of user password is requested again.