Infiniti FX35 / FX45. Manual - part 530

DTC P0181 FTT SENSOR

EC-881

< SERVICE INFORMATION >

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DTC P0181 FTT SENSOR

Component Description

INFOID:0000000001326706

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>

*: These data are reference values and are 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

INFOID:0000000001326707

DTC Confirmation Procedure

INFOID:0000000001326708

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-III

1.

Turn ignition switch ON and wait at least 10 seconds.

2.

Check 1st trip DTC.

3.

If 1st trip DTC is detected, go to 

EC-883, "Diagnosis Procedure"

.

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

4.

Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.

5.

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.

6.

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

°

C (140

°

F).

7.

Wait at least 10 seconds.

8.

Check 1st trip DTC.

PBIB1507E

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/per-
formance

Rationally incorrect voltage from the sensor is 
sent to ECM, compared with the voltage signals 
from engine coolant temperature sensor and in-
take air temperature sensor.

• Harness or connectors

(The sensor circuit is open or shorted)

• Fuel tank temperature sensor

EC-882

< SERVICE INFORMATION >

[VK45DE]

DTC P0181 FTT SENSOR

9.

If 1st trip DTC is detected, go to 

EC-883, "Diagnosis Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT-III” above.

Wiring Diagram

INFOID:0000000001326709

TBWM1334E

DTC P0181 FTT SENSOR

EC-883

< SERVICE INFORMATION >

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Diagnosis Procedure

INFOID:0000000001326710

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

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

EC-723, "Ground Inspection"

.

OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace ground connections.

2.

CHECK DTC WITH “UNIFIED METER AND A/C AMP.”

Refer to 

DI-27, "CONSULT-III Function (METER/M&A)"

.

OK or NG

OK

>> GO TO 3.

NG

>> Go to 

DI-19, "Fuel Level Sensor Signal Inspection"

.

3.

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

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

3.

Turn ignition switch ON.

4.

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

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors B1, M11
• Harness for open or short between ECM and “fuel level sensor unit and fuel pump”

PBIB2195E

PBIB1507E

Voltage: Approximately 5V

PBIB0932E

EC-884

< SERVICE INFORMATION >

[VK45DE]

DTC P0181 FTT SENSOR

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

5.

CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect “unified meter and A/C amp.” harness connector.

3.

Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and “unified meter and
A/C amp.” terminal 36. Refer to Wiring Diagram.

4.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6.

DETECT MALFUNCTIONING PART

Check the following.
• Harness connectors B1, M11
• Harness for open or short between “fuel level sensor unit and fuel pump” and “unified meter and A/C amp.”

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

7.

CHECK FUEL TANK TEMPERATURE SENSOR

Refer to 

EC-884, "Component Inspection"

.

OK or NG

OK

>> GO TO 8.

NG

>> Replace “fuel level sensor unit and fuel pump”.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-717

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326711

FUEL TANK TEMPERATURE SENSOR

1.

Remove fuel level sensor unit.

2.

Check resistance between “fuel level sensor unit and fuel pump”
terminals 4 and 5 by heating with hot water.

Removal and Installation

INFOID:0000000001326712

FUEL TANK TEMPERATURE SENSOR

Refer to 

FL-4

.

Continuity should exist.

Temperature 

°

C (

°

F)

Resistance k

Ω

20 (68)

2.3 - 2.7

50 (122)

0.79 - 0.90

PBIB0931E