TIAGO

ELECTRICAL

121

Immobilizer:

Key ring illumination:

PIN

SIGNAL NAME

KEY RING SUPPLY

GND

Immobilizer earthing:

PIN

SIGNAL NAME

IMMO GND

IMMOBILIZER WORKING PRINCIPLE:

The EMS ECU and the immobilizer are paired together by an encrypted secret code called as “AES secret

key”, to improve the security of the vehicle. This AES secret key is generated using the vehicle identification

number (VIN) and it is unique for each vehicle. Both immobilizer and the EMS ECU are programmed with

same secret key for mutual authentication. If any one of EMS or ICU has different/ wrong secret key, vehicle

will be locked (engine cannot be started).

If EMS or Immobilizer is changed in a vehicle, it is required pairing operation (EMS ECU & ICU programmed

with same secret key) for proper mutual authentication. The pairing of EMS and Immobilizer can be done

through diagnostic tester.

These E-keys are learned for that immobilizer and are unique to that Immobilizer & vehicle. The E-key of other

vehicles will not work with this immobilizer and vice versa.

If anyone of the E-key is lost, it is recommended to approach TATA AUTHORIZED dealer for new E-key. It is

possible to learn new keys with the help of diagnostic tester (Refer the key learning procedure). If both the

keys are lost, it is not be possible to learn the new keys for that immobilizer, as original key is required during

E-key learning operation.

IMMOBILIZER SYSTEM STATUS:



During Ignition off, immobilizer status bulb (“Lock” symbol on the instrument cluster) blinks, indicating

Immobilizer is awaiting E-key.



When the ignition key is turned to the “ON” position, if the status bulb goes OFF indicates that the

system is working and the vehicle is unlocked (Engine is ready to start). If the status bulb is continuously

ON, there may be something wrong with key or with the immobilizer system.