Nissan Maxima. Manual - part 446

EC-268

< DTC/CIRCUIT DIAGNOSIS >

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P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

2. Listen to each fuel injector operating sound.
Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Perform trouble diagnosis for FUEL INJECTOR, refer to

EC-496, "Diagnosis Procedure"

.

7.

CHECK FUEL INJECTOR

1. Remove fuel injector assembly. Refer to 

EM-43, "Removal and Installation"

.

Keep fuel hose and all fuel injectors connected to fuel tube.

2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.

3. Disconnect all fuel injector harness connectors.

4. Disconnect all ignition coil harness connectors.

5. Prepare pans or saucers under each fuel injector.

6. Crank engine for about 3 seconds.

Check that fuel does not drip from fuel injector.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Replace the fuel injectors from which fuel is dripping. Refer to 

EM-43, "Removal and Installation"

.

Always replace O-ring with new one. 

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-41, "Intermittent Incident"

.

>> INSPECTION END

PBIB3332E

P0181 FTT SENSOR

EC-269

< DTC/CIRCUIT DIAGNOSIS >

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P0181 FTT SENSOR

Description

INFOID:0000000010094961

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 terminals 95 (Fuel tank temperature sensor) and 104 (sensor
ground).

DTC Logic

INFOID:0000000010094962

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

INSPECTION START

Is it necessary to erase permanent DTC?

YES

>> GO TO 7.

NO

>> GO TO 2.

2.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-

dure before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-I

1. Turn ignition switch ON and wait at least 10 seconds.

2. Check 1st trip DTC.

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

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0181

FTT SENSOR
[Fuel tank temperature (FTT) 
sensor circuit range/perfor-
mance]

A)

Rationally incorrect voltage from the 
sensor is sent to ECM, compared with 
the voltage signals from ECT sensor 
and intake air temperature sensor.

• Harness or connectors

(The FTT sensor circuit is open or 
shorted)

• FTT sensor
• Combination meter

B)

The comparison result of signals trans-
mitted to ECM from each temperature 
sensor (IAT sensor, ECT sensor, EOT 
sensor, and FTT sensor) shows that 
the voltage signal of the FTT sensor is 
higher/lower than that of other temper-
ature sensors when the engine is start-
ed with its cold state.

• Harness or connectors

(High or low resistance in the FTT 
sensor circuit)

• FTT sensor

EC-270

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0181 FTT SENSOR

Is 1st trip DTC detected?

YES

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

CHECK ENGINE COOLANT TEMPERATURE

With CONSULT

1. Select “COOLAN TEMP/S” in “DATA MONITOR” with CONSULT.

2. Check “COOLAN TEMP/S” value.

With GST

Follow the procedure “With CONSULT” above.
“COOLAN TEMP/S” less than 60

°C (140°F)?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-II

With CONSULT

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

°C (140°F).

2. Wait at least 10 seconds.

3. Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT” above.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

NO

>> GO TO 6.

6.

PERFORM COMPONENT FUNCTION CHECK (FOR MALFUNCTION B)

Perform component function check. Refer to 

EC-271, "Component Function Check"

.

NOTE:

Use the component function check to check the overall function of the FTT sensor circuit. During this check, a

1st trip DTC might not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

7.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-

dure before conducting the next test.

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Turn ignition switch ON.

3. Turn ignition switch OFF and wait at least 10 seconds.

TESTING CONDITION:

• Before performing the following procedure, do not add fuel.

• Before performing the following procedure, check that fuel level is between 1/4 and 4/4.

• Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.

>> GO TO 8.

8.

PERFORM DTC CONFIRMATION PROCEDURE B

1. Start engine and let it idle for 60 minutes.

2. Move the vehicle to a cool place.

NOTE:

Cool the vehicle in an environment of ambient air temperature between 

−10°C (14°F) and 35°C (95°F).

3. Turn ignition switch OFF and soak the vehicle for 12 hours.

CAUTION:

Never turn ignition switch ON during soaking.

NOTE:

The vehicle must be cooled with the food open.

4. Start engine and let it idle for 5 minutes or more.

P0181 FTT SENSOR

EC-271

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CAUTION:

Never turn ignition switch OFF during idling.

5. Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Component Function Check

INFOID:0000000010094963

1.

CHECK FUEL TANK TEMPERATURE (FTT) SENSOR

1. Turn ignition switch OFF.

2. Disconnect fuel level sensor unit and fuel pump harness connector.

3. Remove fuel level sensor unit. Refer to 

FL-6, "Removal and Installation"

.

4. Check resistance between fuel level sensor unit and fuel pump

terminals by heating with hot water as shown in the figure.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

2.

CHECK INTERMITTENT INCIDENT

Check intermittent incident. Refer to 

GI-41, "Intermittent Incident"

.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Proceed to 

EC-271, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000010094964

Regarding Wiring Diagram information, refer to 

EC-554, "Wiring Diagram"

.

1.

INSPECTION START

Confirm the detected malfunction (A or B). Refer to 

EC-269, "DTC Logic"

.

Which malfunction is detected?

A

>> GO TO 2.

B

>> GO TO 7.

2.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in 

GI-44, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace ground connection.

3.

CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect “fuel level sensor unit and fuel pump” harness connector.

3. Turn ignition switch ON.

Terminals

Condition

Resistance (k

Ω)

4 and 5

Temperature [

°C (°F)]

20 (68)

2.3 – 2.7

50 (122)

0.79 – 0.90

JMBIA0167ZZ