Infiniti M45 (Y34). Manual — part 398

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

EC-281

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EC

6.

DETECT MALFUNCTIONING PART

Check the following.

●

Fuel pump and circuit (Refer to

EC-519

,

EC-674

.)

●

Fuel pressure regulator (Refer to

EC-48

.)

>> Repair or replace.

7.

CHECK MASS AIR FLOW SENSOR

With CONSULT-II

1.

Install all removed parts.

2.

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

With GST

1.

Install all removed parts.

2.

Check mass air flow sensor signal in MODE 1 with GST.

OK or NG

OK

>> GO TO 8.

NG

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

grounds. Refer to

EC-174, "DTC P0101 MAF SENSOR"

.

3.8 - 5.2 g·m/sec:

at idling

16.0 - 21.5 g·m/sec:

at 2,500 rpm

3.8 - 5.2 g·m/sec:

at idling

16.0 - 21.5 g·m/sec:

at 2,500 rpm

EC-282

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION

8.

CHECK FUNCTION OF INJECTORS

With CONSULT-II

1.

Start engine.

2.

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

3.

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

Without CONSULT-II

1.

Start engine.

2.

Listen to each injector operating sound.

OK or NG

OK

>> GO TO 9.

NG

>> Perform trouble diagnosis for

EC-661, "INJECTOR CIRCUIT"

.

9.

CHECK INJECTOR

1.

Turn ignition switch OFF.

2.

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

3.

Remove injector assembly. Refer to

EM-31, "FUEL INJECTOR AND FUEL TUBE"

.

Keep fuel hose and all injectors connected to injector gallery.

4.

Disconnect all injector harness connectors.

5.

Disconnect all ignition coil harness connectors.

6.

Prepare pans or saucers under each injectors.

7.

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

OK or NG

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

10.

CHECK INTERMITTENT INCIDENT

Refer to

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

.

>> INSPECTION END

PBIB0133E

Clicking noise should be heard.

PBIB1986E

DTC P0181 FTT SENSOR

EC-283

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EC

DTC P0181 FTT SENSOR

PFP:22630

Component Description

ABS002I2

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>

*: This data is reference values and is measured between ECM terminal 92 (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

ABS002I3

DTC Confirmation Procedure

ABS002I4

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 1st trip DTC is detected, go to

EC-286, "Diagnostic Procedure"

.
If 1st trip DTC is not detected, 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-286, "Diagnostic Procedure"

.

PBIB1127E

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 sig-
nals 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-284

DTC P0181 FTT SENSOR

WITH GST

Follow the procedure WITH CONSULT-II above.