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: 52 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.

P0112-11: Air temperature sensor electrical failure (circuit short to ground)

Overview:

DTC Description as per ISO standard

Air temperature sensor electrical failure (circuit short to

ground)

ECU Pin Number

K76

Customer Symptom

MIL ON.

Fault Effects (On Vehicle)

Cruise control off

Lamp Status (If Any)

MIL ON

Fault Detection Condition (Root cause)

Ignition ON engine ON

Normal Operating Condition

Fault condition no more present.

Probable Trouble Area

1. Repair the (K76) Intake Air Temperature Sensor Signal

circuit for a short to ground.

2. Repair the (K87) MAF Sensor Ground circuit for a short to

ground.

3. Repair the (K76) Intake Air Temperature Sensor Signal

circuit for an open or high resistance.

4. Air mass sensor

5. EMS ECU

Healing Condition

Rectify the error

Clear through diagnostic tool

Ignition OFF & ON

Component Details:

The operating principle is based on the heating of a diaphragm (sensitive element containing two resistances upstream

and downstream of the support) in a by-pass duct through which the engine intake air flows. The hot film membrane is

maintained at constant temperature (about 120 °C higher than the incoming air temperature) by the specific heating

resistance controlled by the management electronics. The mass of air passing through the by-pass duct, giving off heat to

the membrane, thermally unbalances the two resistances to an extent directly proportional to the mass of the incoming

fluid, an imbalance that is translated through the control circuit into a resistance variation, electronically processed and

translated into a frequency value to be sent to the engine management control unit. The imbalance in the resistance value

also makes it possible to determine the direction of the column of air. As far as the air temperature information is

concerned, it is sent to the engine management control unit via a dedicated pin in the form of a duty cycle signal

(rectangular wave). The value of the duty is proportional to the value of the temperature

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. Check whether the EMS is receiving Battery supply and Ground.

4. Check whether the Battery is healthy.

5. Check air and fuel system.

6. Air filter clogged.

7. Air mass flow sensor connection.