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Immobilizer –DTC Troubleshooting Data
Version: 1.
2
Date:
03-June-2014
Prepared Author
:
Sarang K/Mithipati P
Review & approved by
: R A Rode (ERC-E&E)
Page: 18 of 67
Copyright ©
TATA MOTORS Ltd.
This document must not be used in any way, such as copying and redistributing to third parties, without the consent of author.
B1639-81: Vehicle Immobilizer Control Module Invalid Data Received
Overview:
ISO Code
B1639-81
DTC simple Description
EMS-Immobilizer communication failure
Customer Symptom
Vehicle cannot be started.
Fault Effects (On Vehicle)
Vehicle cannot be started.
Lamp Status (If Any)
Immo status lamp On
Fault Detection Condition
At ignition On
Normal Operating Condition Authentication between EMS & Immo is successful
Probable Trouble Area
EMS ECU, Immobilizer
Healing Condition
Component Details:
Immobilizer system is designed to prevent vehicle theft by electronically disabling the engine starting
system. The engine can be started only with vehicle’s original immobilizer ignition key, which has an electronic
identification programmed code. Immobilizer unit (ICU) is an add-on part on the ignition switch, fitted on the
steering column. The engine can be started only with the vehicle’s original immobilizer ignition key. The electronic
key communicates the identification code to ICU when the key is turned to the "Ignition ON" position.
Preliminary Checks:
2.
EMS & immobilizer are paired or not.
3.
EMS & Immobilizer written with same VIN
4.
EMS ECU is connected in vehicle or not.
5.
EMS ECU supply & Gnd connections
Trouble Shooting:-
Step Checks
IF YES
IF NO
1. Vehicle EMS ECU is connected
Go to next step
Connect the EMS
ECU
2. EMS & immobilizer are paired or not
Go to next step
Pair the EMS ECU
3. EMS ECU supply & Gnd connections are Ok
Go to next step
Correct the supply
& Gnd connection
4 VIN in EMS & immobilizer must be same
Go to next step
If ECU is not lock
try to repair.
5 Replace the EMS ECU with new good one
Go to next step
-
6
Pair the EMSECU with immobilizer using TATA
diagnostic tool & verify the VIN in EMS & immobilizer
should be same.
Go to next step
-
7. Crank the vehicle before locking the EMS ECU.
Go to next step
8. Vehicle should be start successfully.
Go to next step
9. Lock the EMS ECU
Stop
DTC’s confirmation:-
Check the status of immobilizer in EMS ECU.
Start the EMS ECU diagnostic tool
Go to Engine parameter