General Information

Immobilizer III, On Board Diagnostic (OBD)


NOTE:
- For the immobilizer III, the Engine Control Module (ECM) is actively incorporated into the evaluation and monitoring. The control module For immobilizer is integrated into the instrument cluster.







- For immobilizer III, the keys are marked with an inscribed "W". The code consists of a fixed code and a variable code portion.

Function
Immobilizer III consists of:
- an adapted control module For anti-theft immobilizer (integrated in instrument cluster)
- a warning light in instrument cluster
- an induction coil at ignition lock
- an adapted Engine Control Module (ECM)
- and adapted ignition keys with electronics (transponder).

The control module For anti-theft immobilizer is integrated in the instrument cluster, e.g. if control module is malfunctioning, instrument cluster must be replaced.

The anti-theft immobilizer is a system For enabling/locking the Engine Control Module (ECM) via the CAN wire.

The transponder code consists of a fixed code and a variable code. This is different For every start procedure and therefore acts as a copy protection For the transponder.

Ever immobilizer contains a different computational rule For the variable code that remains the same For its entire service life. During adaptation of the vehicle key, the immobilizer writes this computational rule into the transponder and simultaneously learns the fixed code of the current key.

The fixed code identifies each individual key so that a key that is lost can be blocked from usage. Each time the ignition is switched on, the induction coil For immobilizer reads the transponder's fixed code and then the variable code and determines whether this key is authorized For vehicle start.

The warning lamp lights up briefly (max. 3 seconds) and then goes out when an authorized vehicle key is used.

When an unauthorized vehicle key is used or when a system malfunction occurs, the warning lamp blinks constantly during ignition "on".

The electronic anti-theft immobilizer is capable of extensive On Board Diagnostic (OBD). If malfunctions occur in any of the system components, corresponding Diagnostic Trouble Codes (DTC) are stored in the DTC memory of the anti-theft immobilizer. Malfunctions can be determined via VAS5051 tester.


NOTE: The following description refers only to the VAS5051 fester.


Note For use and adaptation of vehicle key

Engine will only start when an authorized vehicle key is used, i.e. on of the keys adapted to the immobilizer.

During adaptation of the vehicle keys, all vehicle keys, including replacement and emergency keys, must always be adapted to the immobilizer.

If new or extra vehicle keys are required, adaptation of all vehicle keys must be performed.

If adaptation cannot be performed For all vehicle keys, e.g. key lost during a trip, the customer must be informed that adaptation must eventually be performed For any and all vehicle keys.

Especially when a key has been lost, all vehicle keys should be re-adapted, since this will render the lost key unauthorized For vehicle start.