Nissan Altima L32. Manual - part 538

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-1273

< COMPONENT DIAGNOSIS >

[VQ35DE]

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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-1483, "Diagnosis Procedure"

.

7.

CHECK FUEL INJECTOR

1. Remove fuel injector assembly. Refer to 

EM-146, "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 approximately 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. Always replace O-ring with new one. 

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

PBIB3332E

EC-1274

< COMPONENT DIAGNOSIS >

[VQ35DE]

P0181 FTT SENSOR

P0181 FTT SENSOR

Description

INFOID:0000000004362113

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:0000000004362114

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing 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 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE-I

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

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

YES

>> Go to 

EC-1275, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

CHECK ENGINE COOLANT TEMPERATURE

With CONSULT-III

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

2. Check “COOLAN TEMP/S” value.

With GST

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

°C (140°F)?

YES

>> INSPECTION END

NO

>> GO TO 4.

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

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

P0181 FTT SENSOR

EC-1275

< COMPONENT DIAGNOSIS >

[VQ35DE]

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4.

PERFORM DTC CONFIRMATION PROCEDURE-II

With CONSULT-III

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-III” above.
Is 1st trip DTC detected?

YES

>> Go to 

EC-1275, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000004362115

1.

CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

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

GI-45, "Circuit Inspection"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace ground connection.

2.

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.

4. Check the voltage between “fuel level sensor unit and fuel

pump” harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors B10, E29

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

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

4.

CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between “fuel level sensor unit and fuel pump” harness connector and ECM harness

connector.

4. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 6.

Fuel level sensor unit and fuel pump

Ground

Voltage

Connector

Terminal

B42

4

Ground

Approx. 5 V

PBIB0932E

Fuel level sensor unit and fuel pump

ECM

Continuity

Connector

Terminal

Connector

Terminal

B42

5

E10

104

Existed

EC-1276

< COMPONENT DIAGNOSIS >

[VQ35DE]

P0181 FTT SENSOR

NO

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors B1, M6

• Harness connectors E30, M1

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

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

6.

CHECK FUEL TANK TEMPERATURE SENSOR

Refer to 

EC-1276, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

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

7.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004362116

1.

CHECK FUEL TANK TEMPERATURE SENSOR

1. Turn ignition switch OFF.

2. Remove fuel level sensor unit.

3. 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

>> INSPECTION END

NO

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

Terminals

Condition

Resistance

4 and 5

Temperature [

°C (°F)]

20 (68)

2.3 - 2.7 k

Ω

50 (122)

0.79 - 0.90 k

Ω

PBIB0931E