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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: 20 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.
B1639-31: Vehicle immobilizer control module no signal
Overview:
ISO Code
B1639-31
DTC simple Description
EMS is not transmitting CAN message
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
W/h, 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 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:
1
. Check the CAN H & CANL wires between EMS & Immobilizer.
2. EMS ECU supply & Gnd wires
.
Trouble Shooting:-
Step Checks
IF YES
IF NO
1.
Check the EMS ECU is connector connected to ECU
Go to step 1
Connect EMS ECU
2.
Check the EMS ECU supply & Gnd wires are properly
connected
Go to step 2
Correct the
connection
3
Check the CAN H & CAN L wires continuity between EMS
ECU pin (CAN H 64, CAN L 40) & Immobilizer pin (CANH
3, CAN L 8)
Go to step 3
Correct the
connection
4
Check the resistance between CAN H & CAN L at immo pin
3 & 8, it should be 60±5
Ω
Go to step 4
Check any short
circuit in w/h.
5
Replace the EMS ECU with new good one & pair the ECU
with immobilizer.
6
If fault still present in immobilizer replace the immobilizer
DTC’s confirmation:-
Before handover to customer, ensure that vehicle will start without any error
Circuit Schematic Diagram:
Please refer the immobilizer circuit schematic
VICM
pin
no
Pin description
1
Vbatt (KL30)
2
GND
3
CAN_H(High-speed)
4
Ignition (KL15)