HARRIER BOOK 2

Transponder & CAN based Immobilizer (Continental)

Part Replacement handling – Service Documentation

TITLE

: Immobilizer (Conti) Service Manual-Aria Eagle

xxxx

Date

: 28-08-2015

Version

: 0.1

Page

7 of 25

Prepared :

Amanulla Bugga

Approved: Dinesh G Dodmane

This specification is the exclusive property of Tata Motors Limited. Without their consent it may not be

reproduced or given to third parties

The above specifications are subject to change and therefore

suppliers are requested to refer the latest one.

CONTROLLED COPY FOR RESTRICTED CIRCULATION

1.4.

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) which 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 requires pairing operation, for proper mutual

authentication. The pairing of EMS and Immobilizer can be done through diagnostic tester.

Immobilizer comes with two Electronic keys (E-key). 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 dealer for new E-key. It is possible to

learn new keys with the help of diagnostic tester.

(Refer the key learning procedure - section 6.1).

If both E-keys are lost it is recommended to approach dealer for new E-key. It is possible to learn

new keys with the help of diagnostic tester.

(Refer the key learning procedure - section 6.2).

Immobilizer system status:

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

slow rate), indicating Immobilizer is awaiting E-key.

When the ignition key is turned to the "ON" position,

If the status lamp goes OFF, it indicates that the system is working and the vehicle is

unlocked (Engine is ready to start).

If the status lamp is continuously ON, then there may be something wrong in system

(key, wiring harness, EMS ecu or immobilizer).

CAN Wakeup:

Generally Immobilizer wake up with Ignition supply input. However when ignition supply of

immobilizer unit fails, then Immobilizer wakes up on CAN messages received form EMS.

This is the new feature which avoids the vehicle start disabling when immobilizer ignition

supply fails.

Immobilizer status LED in instrument cluster continuously blinks at slow rate (though Engine is

unlocked), when ignition supply to Immobilizer unit is missing.

This Immobilizer Status lamp behavior is same as ignition OFF condition, however if engine is

cranked but still Immo status lamp is blinking at slow rate then it indicates that Ignition supply

to Immobilizer unit is missing.