HARRIER BOOK 2

Q501 4 Cylinder MT Application

DTC Troubleshooting Data

Version: 0.1

Date: 21-Sep-2018

Prepared By: Mithi Prasad, Sarang Kulkarni, Manish Gupta

Checked By: Yogesh Jadhav

Approved By: Satish Kumar P

Page: 73 of 1052

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.

U0073-88: Control Module Communication Bus "A" Off : CAN Bus off

Overview:

DTC Description (User Friendly)

Control Module Communication Bus "A" Off: CAN Bus off.

ECU Pin Number

K013 – CAN_H

K014 – CAN_L

A075 – Ignition

K001, K003, K005 – Supply voltage battery

K002, K004, K006 - Ground voltage battery

Customer Symptom

MIL OFF, CEL ON.Check engine lamp will be ON.

Fault Effects (On Vehicle)

Vehicle will not start.

Lamp Status (If Any)

CEL ON. CEL Turns Off as and when fault condition is not

present / healed.

Fault Detection Condition (Root cause)

1. Short circuit between CAN_H -CAN_L, CAN_H –

GND, CAN_L-Vbatt, CAN_L-GND and/or

CAN_H- Vbatt

2. Open circuit of CAN_H/ CAN_L/ both lines

3. When CAN BusOff Failure is detected

Normal Operating Condition

ECM ECU communicates properly with other partner

ECUs in the CAN network.

Probable Trouble Area

CAN_H and CAN_L wires.

Healing Condition

1. Removal of the above mentioned shorts in the

wiring harness or at ECU pin.

2. Reconnecting CAN_H/ CAN_L/ both lines to

ECM ECU.

Component Details:

ECM ECU communicates properly with other partner ECUs in the CAN network.

Preliminary Checks:

1. Check whether the customer voice / view about the issue is matching with the fault effects mentioned in above

Table. If yes, go ahead with next steps. If not, check for other DTC’s presence.

2. Check whether other customers report similar complaints earlier. If yes, perform the preliminary checks with

respect to earlier issue closure.

3. Check for Damage in EMS ECU connector / Other ECU Connector.

4. Check for any back out of pins at EMS ECU connector / Other ECU Connector.

5. Check for any damage of pins at EMS ECU connector / Other ECU Connector.

Trouble Shooting: