Infiniti M35/M45 Y50. Manual - part 642

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-1041

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4. 

CHECK FUEL PRESSURE

1.

Release fuel pressure to zero. Refer to 

EC-790, "FUEL PRESSURE RELEASE"

 .

2.

Install fuel pressure gauge and check fuel pressure. Refer to 

EC-791, "FUEL PRESSURE CHECK"

 .

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Fuel pump and circuit (Refer to 

EC-1395, "FUEL PUMP"

 .)

●

Fuel pressure regulator (Refer to 

EC-791, "FUEL PRESSURE CHECK"

 .)

>> Repair or replace.

6. 

CHECK MASS AIR FLOW SENSOR

 With CONSULT-II

1.

Install all removed parts.

2.

Start engine and warm it up to normal operating temperature.

3.

Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.

 With GST

1.

Install all removed parts.

2.

Start engine and warm it up to normal operating temperature.

3.

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

OK or NG

OK (With CONSULT-II)>>GO TO 7.
OK (Without CONSULT-II)>>GO TO 8.
NG

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

grounds. Refer to 

EC-906, "DTC P0101 MAF SENSOR"

 .

7. 

CHECK FUNCTION OF FUEL INJECTOR

 With CONSULT-II

1.

Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.

2.

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

At idling: Approximately 350 kPa (3.57 kg/cm

2

 , 51 psi)

2.0 - 6.0 g·m/sec:

at idling

7.0 - 20.0 g·m/sec:

at 2,500 rpm

2.0 - 6.0 g·m/sec:

at idling

7.0 - 20.0 g·m/sec:

at 2,500 rpm

PBIB0133E

EC-1042

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DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

OK or NG

OK

>> GO TO 9.

NG

>> Perform trouble diagnosis for 

EC-1389, "FUEL INJECTOR"

 .

8. 

CHECK FUNCTION OF FUEL INJECTOR

 Without CONSULT-II

Listen to fuel injector operating sopund.

OK or NG

OK

>> GO TO 9.

NG

>> Perform trouble diagnosis for 

EC-1389, "FUEL INJEC-

TOR"

 .

9. 

CHECK FUEL INJECTOR

1.

Remove fuel tube assembly. Refer to 

EM-193, "FUEL INJECTOR AND FUEL TUBE"

 .

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 injectors.

6.

Crank engine for about 3 seconds.
Make sure fuel does not drip from fuel injector.

OK or NG

OK (Does not drip.)>>GO TO 10.
NG (Drips.)>>Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one. 

10. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-857, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Operating sound should exist.

PBIB1986E

DTC P0181 FTT SENSOR

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EC

DTC P0181 FTT SENSOR

PFP:22630

Component Description

NBS005FH

The fuel tank temperature sensor (3) is used to detect the fuel tem-
perature inside the fuel tank. The sensor modifies a voltage signal
from the ECM. The modified signal returns to the ECM as the fuel
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

●

Fuel level sensor unit and fuel pump (1)

●

Fuel pressure regulator (2)

<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

NBS005FI

DTC Confirmation Procedure

NBS005FJ

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 the result is NG, go to 

EC-1046, "Diagnostic Procedure"

 .

If the result is OK, 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-1046, "Diagnostic Procedure"

 .

PBIB2707E

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 signals 
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-1044

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DTC P0181 FTT SENSOR

 WITH GST

Follow the procedure “WITH CONSULT-II” above.