Nissan GT-R (R35) · Service Manual ENGINE

P0125 ECT SENSOR

VR38

P0125

Description


The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.

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<Reference data>

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Engine coolant temperature
[°C (°F)]
Voltage*　(V)
Resistance　(kΩ)
–10 (14)
4.4
7.0 - 11.4
20 (68)
3.5
2.1 - 2.5
50 (122)
2.3
0.68 - 1.00
90 (194)
0.9
0.236 - 0.260
*: These data are reference values and are measured between ECM terminals 46 (Engine coolant temperature sensor) and 26 (Sensor ground).

DTC Logic

 
 DTC DETECTION LOGIC

NOTE：
 If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 , P0118. Refer to DTC Logic (GT-R certified NISSAN dealer).

DTC No.
 		Trouble diagnosis name
 		DTC detecting condition
 		Possible cause
P0125
 		Insufficient engine coolant temperature for closed loop fuel control
  • Voltage sent to ECM from the sensor is not practical, even when some time has passed after starting the engine.
  • Engine coolant temperature is insufficient for closed loop fuel control.
  • Harness or connectors
    (High resistance in the circuit)
  • Engine coolant temperature sensor
  • Thermostat

 
 DTC CONFIRMATION PROCEDURE

 
 1.PRECONDITIONING
 
 2.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
 
 3.PERFORM DTC CONFIRMATION PROCEDURE

Diagnosis Procedure


 
 1.CHECK GROUND CONNECTION
 
 2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
 
 3.CHECK THERMOSTAT OPERATION
 
 4.CHECK INTERMITTENT INCIDENT

Component Inspection


 
 1.CHECK ENGINE COOLANT TEMPERATURE SENSOR