Infiniti Q45. Manual - part 425

DTC P0181 FTT SENSOR

EC-339

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EC

DTC P0181 FTT SENSOR

PFP:22630

Component Description

NBS001VE

The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

<Reference data>

*: This data is reference value and is measured between ECM terminal 107 (Fuel
tank temperature sensor) and ground.

CAUTION:

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

On Board Diagnosis Logic

NBS001VF

DTC Confirmation Procedure

NBS001VG

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.

Wait at least 10 seconds.
If 1st trip DTC is detected, go to 

EC-342, "Diagnostic Procedure"

.
If 1st trip DTC is not detected, go to following step.

4.

Check “COOLAN TEMP/S” value.
If “COOLAN TEMP/S” is less than 60

°

C (140

°

F), the result will

be OK.
If “COOLAN TEMP/S” is above 60

°

C (140

°

F), go to the following

step.

5.

Cool engine down until “COOLAN TEMP/S” is less than 60

°

C (140

°

F).

6.

Wait at least 10 seconds.

7.

If 1st trip DTC is detected, go to 

EC-342, "Diagnostic Procedure"

 .

PBIB1249E

Fluid temperature

°

C (

°

F)

Voltage*

V

Resistance

k

Ω

20 (68)

3.5

2.3 - 2.7

50 (122)

2.2

0.79 - 0.90

SEF012P

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0181
0181

Fuel tank temperature 
sensor circuit range/
performance

Rationally incorrect voltage from the sensor is 
sent to ECM, compared with the voltage sig-
nals from engine coolant temperature sensor 
and intake air temperature sensor.

●

Harness or connectors
(The sensor circuit is open or shorted)

●

Fuel tank temperature sensor

SEF174Y

EC-340

DTC P0181 FTT SENSOR

 WITH GST

Follow the procedure WITH CONSULT-II above.

DTC P0181 FTT SENSOR

EC-341

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EC

Wiring Diagram

NBS001VH

TBWM0547E

EC-342

DTC P0181 FTT SENSOR

Diagnostic Procedure

NBS001VI

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten three ground screws on the body.
Refer to 

EC-154, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2. 

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1.

Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.

2.

Turn ignition switch ON.

3.

Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors B211, M141

●

Harness connectors M135, F105

●

Harness for open or short between ECM and “fuel level sensor unit and fuel pump”

>> Repair open circuit or short to ground or short to power in harness or connector.

PBIB2417E

PBIB1249E

Voltage: Approximately 5V

PBIB0316E