Nissan Sentra. Manual - part 389

EC-252

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0172 FUEL INJECTION SYSTEM FUNCTION

*1: Except California

*2: For California

6. Also check harness for short to power.
Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair or replace error-detected parts.

4.

CHECK FUEL PRESSURE

Check fuel pressure. Refer to 

EC-143, "Work Procedure"

.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

 DETECT MALFUNCTIONING PART

Check fuel hoses and fuel tubes for clogging. Refer to 

EM-40, "Exploded View"

.

Is the inspection result normal?

YES

>> Replace “fuel filter and fuel pump assembly”. Refer to 

FL-6, "Exploded View"

.

NO

>> Repair or replace error-detected parts.

6.

CHECK MASS AIR FLOW SENSOR

With CONSULT

1. Install all removed parts.

2. Check “MASS AIR FLOW” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

3. For specification, refer to 

EC-486, "Mass Air Flow Sensor"

.

With GST

1. Install all removed parts.

2. Check mass air flow sensor signal in Service $01 with GST.

3. For specification, refer to 

EC-486, "Mass Air Flow Sensor"

.

Is the measurement value within the specification?

YES

>> GO TO 7.

NO

>> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or

grounds. Refer to 

EC-186, "DTC Logic"

.

7.

CHECK FUNCTION OF FUEL INJECTOR

With CONSULT

1. Start engine.

2. Perform “POWER BALANCE” in “ACTIVE TEST” mode of “ENGINE” using CONSULT.

3. Make sure that each circuit produces a momentary engine speed drop.

Without CONSULT

1. Let engine idle.

+

−

Continuity

A/F sensor 1

Connector

Terminal

F12

*1

F42

*2

1

Ground

Not existed

2

+

−

Continuity

ECM

Connector

Terminal

F24

41

Ground

Not existed

45

P0172 FUEL INJECTION SYSTEM FUNCTION

EC-253

< DTC/CIRCUIT DIAGNOSIS >

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2. Listen to each fuel injector operating sound.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Perform trouble diagnosis for “FUEL INJECTOR”. Refer

to 

EC-450, "Component Function Check"

.

8.

CHECK FUEL INJECTOR

1. Turn ignition switch OFF.

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. Remove fuel tube assembly. Refer to 

EM-40, "Removal and Installation"

.

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

5. Disconnect all ignition coil harness connectors.

6. Prepare pans or saucers under each fuel injector.

7. Crank engine for about 3 seconds.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-39, "Intermittent

Incident"

.

NO

>> Replace fuel injectors from which fuel does not spray

out. Always replace O-ring with new ones. Refer to 

EM-

40, "Removal and Installation"

.

Clicking noise should be heard.

PBIB3332E

Fuel should be sprayed evenly for each fuel injector.

PBIA9666J

EC-254

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P0181 FTT SENSOR

P0181 FTT SENSOR

DTC Logic

INFOID:0000000009758502

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-1

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

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

YES

>> Proceed to 

EC-256, "Diagnosis Procedure"

.

NO

>> GO TO 4.

4.

CHECK ENGINE COOLANT TEMPERATURE

With CONSULT

1. Select “COOLANT TEMP/S” in “DATA MONITOR” of “ENGINE” using CONSULT.

2. Check “COOLANT TEMP/S” value.

With GST

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

°C (140°F)?

YES

>> INSPECTION END

NO

>> GO TO 5.

5.

PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A-2

With CONSULT

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

°C (140°F).

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

P0181

FTT SENSOR
(Fuel temperature sensor 

″A″ 

circuit range/performance)

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

(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

P0181 FTT SENSOR

EC-255

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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-256, "Diagnosis Procedure"

.

NO

>> GO TO 6.

6.

PERFORM COMPONENT FUNCTION CHECK (FOR MALFUNCTION B)

Perform component function check. Refer to 

EC-255, "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-256, "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. 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).

2. Turn ignition switch OFF and leave the vehicle for 12 hours.

CAUTION:

Never turn ignition switch ON during this procedure.

NOTE:

The vehicle must be cooled with the food open.

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

CAUTION:

Never turn ignition switch OFF during idling.

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

YES

>> Proceed to 

EC-256, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Component Function Check

INFOID:0000000009758503

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"

.