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: 704 of 1052
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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.
P0117-11: Engine Coolant Temperature Sensor 1 Circuit Low – Engine coolant temperature sensor signal (circuit
short to ground)
Overview:
DTC Description (User Friendly)
Engine coolant temperature sensor signal (circuit short to
ground)
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 less than 0.22 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 ground.
EMS pin A099 short-circuited to ground.
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.




