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: 707 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.

P0118-15: Engine Coolant Temperature Sensor 1 Circuit High – Engine coolant temperature sensor signal (circuit

short to battery or open)

Overview:

DTC Description (User Friendly)

Engine coolant temperature sensor signal (circuit short to

battery or open)

ECU Pin Number

A100 and A099

Customer Symptom

MIL ON1, Cooling Fans will be running in High Speed

Fault Effects (On Vehicle)

MIL ON1

Lamp Status (If Any)

MIL ON. MIL will be off after 3 warm up cycles (Drive Cycle

with 22 deg Coolant Temperature raise) with fault condition no

more present.

Fault Detection Condition (Root cause)

EMS receive s voltage greater than 4.936 volts at pin A100.

Normal Operating Condition

EMS receives the voltage at pin A100 in range – 0.22 to 4.936

Volts.

Probable Trouble Area

Check, whether there is dis-continuity in wiring harness

between Coolant Temperature Sensor and EMS ECU.

High Resistance in the Engine Coolant Temperature sensor

signal circuit

High Resistance in the Engine Coolant Temperature Sensor

Ground circuit.

EMS Pin A100 Short circuited to Battery / Open circuited.

EMS pin A099 short circuited to Battery or open circuited.

Coolant Temperature sensor faulty

EMS ECU faulty

Healing Condition

Rectify the error

Clear through diagnostic tool

Ignition OFF & ON

Component Details:

The temperature sensing circuit uses Thermistor that is sensitive to change in temperature. It has basically the NTC

(Negative Temperature Coefficient) means as the temperature increases, the resistance decreases. Based on the Engine

coolant temperature, EMS controls the Fuel Injection and cooling fan operation. Engine coolant temperature information

will also be displayed on the Instrument cluster.

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. Loose/ Damaged Connections between Coolant Temperature Sensor and EMS ECU.

4. Check for damage of pins at ECU connector.

5. Check for damage of pins at coolant temperature sensor’s connector.