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: 220 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.

P1087-92: Positive fuel pressure governor deviation (step 2) low pressure (signal above upper limit) -

Performance or Incorrect Operation

Overview:

DTC Description as per ISO standard

Positive fuel pressure governor deviation (step 2) low

pressure (signal above upper limit)- Performance or Incorrect

Operation

ECU Pin Number

K071

Customer Symptom

MIL ON

Fault Effects (On Vehicle)

Cruise control off,

Torque limitation

Regeneration off

Lamp Status (If Any)

MIL ON

Fault Detection Condition (Root cause)

Fuel system

Normal Operating Condition

No Fault Code

Probable Trouble Area

Fuel system leak

Fuel pressure sensor

Fuel injectors

High pressure delivery pump

Fuel system contaminated

Healing Condition

Clear through diagnostic tool

Ignition OFF & ON

Component Details:

Rail pressure sensor is a piezoelectric type one, which is used to measure the fuel pressure inside the Rail. It provides the

Pressure in terms of voltage to the ECU. This rail possesses an under pressure supply of diesel fuel which is ready to be

used by the injectors. The drop of pressure in the rail is immediately signalled by the sensor to the engine control unit.

This is followed by the restoration of pressure in the pump. It is the engine control unit that controls the fuel supply of the

rail from a pump possessing very high pressure. This is done by using a valve for controlling the pressure of fuel

Preliminary Checks:

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

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

2. Check whether similar complaints are earlier reported. If yes, perform the preliminary checks with respect to

earlier issue closure.

3. Fuel circuit

4. Loose/ Damaged Connections between fuel pump relay command and EMS ECU.

5. Check for back out of pins at both fuel pump connector and ECU connector.

6. Check for damage of pins at both fuel pump connector and ECU connector.

7. Atmospheric pressure sensor faulty?