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: 837 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.

P0405-14: EGR Sensor “A” Circuit Low – EGR high pressure valve position sensor electrical test (circuit short to

ground or open)

Overview:

DTC Description (User Friendly)

EGR high pressure valve position sensor electrical test (circuit

short to ground or open)

ECU Pin Number

A040, A079, A078

Customer Symptom

MIL ON, CEL OFF. Increased Nox emissions, possible surging

while driving, intermittent vehicle stall.

Fault Effects (On Vehicle)

Increased Nox emissions, possible surging while driving,

intermittent vehicle stall.

Lamp Status (If Any)

MIL ON, CEL OFF

Fault Detection Condition (Root cause)

EGR position sensor signal received by EMS ECU is less than

0.25 volts.

Normal Operating Condition

No fault

Probable Trouble Area

Wiring Harness connections between EGR position sensor and

EMS ECU

Engine Management System

Healing Condition

Rectify the error

Clear through diagnostic tool

Ignition OFF & ON

Component Details:

An incomplete burnt gas in exhaust is return to the cylinder. EGR works by recalculating a portion of an engine's

exhaust gas back to the engine cylinder. Intermixing the incoming air with recalculated exhaust gas dilutes the mix with

inert gas and in turn reduce the combustion temperatures for reducing NOx emissions.

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 of pins at ECU connector.

4. Check the wiring harness connections between the EGR position sensor and EMS ECU.

Trouble Shooting:

Step Checks

IF YES

IF NO

Run the EGR High Pressure DC Motor Test Routine. Is the

Routine Result – OK?

Go to Next Step

Rectify the wiring

Harness

connections

between EGR

Valve and EMS

ECU. Repeat the

Routine Test again.

If the Routine result

is negative, then