Infiniti F50. Manual - part 390

 

  Index      Infiniti     Infiniti F50 - service repair manual 2006 year

 

Search            

 

 

 

 

 

 

 

 

 

Content   ..  388  389  390  391   ..

 

 

Infiniti F50. Manual - part 390

 

 

DTC P0125 ECT SENSOR

EC-201

C

D

E

F

G

H

I

J

K

L

M

A

EC

DTC P0125 ECT SENSOR

PFP:22630

Component Description

EBS00LYF

NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to 

EC-190, "DTC P0117, P0118 ECT SENSOR"

 .

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 ther-
mistor decreases as temperature increases.

<Reference data>

*: These data are reference values and are measured between ECM terminal 121
(Engine coolant temperature sensor) and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

On Board Diagnosis Logic

EBS00LYG

This self-diagnosis has the one trip detection logic.

SEF594K

Engine coolant 

temperature

°

C (

°

F)

Voltage*

V

Resistance

k

10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.1 - 2.9

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0125
0125

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

EC-202

DTC P0125 ECT SENSOR

DTC Confirmation Procedure

EBS00LYH

CAUTION:

Be careful not to overheat engine.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.

 WITH CONSULT-II

1.

Turn ignition switch “ON”.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Check that “COOLAN TEMP/S” is above 10

°

C (50

°

F).

If it is above 10

°

C (50

°

F), the test result will be OK.

If it is below 10

°

C (50

°

F), go to following step.

4.

Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 10

°

C (50

°

F)

within 65 minutes, stop engine because the test result will
be OK.

5.

If DTC is detected, go to 

EC-204, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “WITH CONSULT-II” above.

SEF174Y

DTC P0125 ECT SENSOR

EC-203

C

D

E

F

G

H

I

J

K

L

M

A

EC

Wiring Diagram

EBS00LYI

TBWM0009E

EC-204

DTC P0125 ECT SENSOR

Diagnostic Procedure

EBS00LYJ

1. 

CHECK ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EC-204, "Component Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Replace engine coolant temperature sensor.

2. 

CHECK THERMOSTAT OPERATION

When the engine is under cold [less than 70

°

C (158

°

F)] condition, grasp lower radiator hose and confirm the

engine coolant does not flow.
OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace thermostat. Refer to 

CO-24, "THERMOSTAT AND WATER CONTROL VALVE"

 .

3. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

EBS00LYK

ENGINE COOLANT TEMPERATURE SENSOR

1.

Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

<Reference data>

*: These data are reference values and are measured between ECM terminal
121 (Engine coolant temperature sensor) and ground.

2.

If NG, replace engine coolant temperature sensor.

Removal and Installation

EBS00LYL

ENGINE COOLANT TEMPERATURE SENSOR

Refer to 

EM-61, "CYLINDER HEAD"

 .

PBIB2005E

Engine coolant 

temperature

°

C (

°

F)

Voltage*

V

Resistance

k

20 (68)

3.5

2.1 - 2.9

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

 

 

 

 

 

 

 

Content   ..  388  389  390  391   ..