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Nexon Gasoline – EMS ECU Bosch
DTC Troubleshooting Manual
Version: 0.1
Date: 26-08-2017
Prepared By: Sunu S Babu/Yogesh Jadhav
Checked By: Yeshwant Jadhav
Approved By: Satish Kumar
Document Part No: 2921 02 224 A1736
Page: 198 of 1203
Copyright ©
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.
Coolant Temperature Sensor:
Technical Principle:
The engine coolant temperature Sensor measures the temperature of the engine coolant. Coolant temperature Sensor
is a Negative Temperature Coefficient type Sensor. The sensing element, together with the resistance network in the
Engine Management System (EMS) module, provides a signal proportional to the coolant temperature to the EMS
module. A reference voltage is provided to the Sensor/network by the module.
The water temperature Sensor, 16TT provides water temperature input to ECU when placed in water stream. The 16TT
has negative temperature coefficient with a 2 pin connector, is a semiconductor material which changes resistance
depending on the surrounding temperature. The resistance decreases as temperature increases. Water temperature
Sensor is mounted on thermostat housing (before thermostat), which is in contact with the engine coolant and
tightened to a specified torque.
Diagnosis
Use multimeter to check for coil resistance across pin 1 and pin 2, which should be between 2500 ohms at 200C and
833.9 ohms at 500C.
1. ECU M1D4 :- -ve
2. ECU M1E4 :- +ve
Use TATA diagnosis tool to check for 'Water
Temp' values.
Resistance and Temperature graph:-