2007 INFINITI M35 fuel

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-1039
[VK45DE]
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Revision: 2007 April2007 M35/M45
Diagnostic ProcedureNBS005FG
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
PBIB1216E

EC-1040
[VK45DE]
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2007 April2007 M35/M45
3. CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding air fuel ratio (A/F) sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
: Vehicle front 1. A/F sensor 1 (bank 2)
harness connector2. A/F sensor 1 (bank 1)
harness connector
A/F sensor 1 terminal ECM terminal
Bank 1116
275
535
656
Bank 2176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
PBIB2715E

DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-1041
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Revision: 2007 April2007 M35/M45
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
[VK45DE]
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2007 April2007 M35/M45
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
EC-1043
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Revision: 2007 April2007 M35/M45
DTC P0181 FTT SENSORPFP:22630
Component DescriptionNBS005FH
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)

*: 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 LogicNBS005FI
DTC Confirmation ProcedureNBS005FJ
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*
VResistance
kΩ
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
0181Fuel tank temperature
sensor circuit range/
performanceRationally 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-1046
[VK45DE]
DTC P0181 FTT SENSOR
Revision: 2007 April2007 M35/M45
Diagnostic ProcedureNBS005FL
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-864, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK DTC WITH “UNIFIED METER AND A/C AMP.”
Refer to DI-31, "
SELF-DIAG RESULTS" .
OK or NG
OK >> GO TO 3.
NG >> Go to DI-22, "
Fuel Level Sensor Signal Inspection" .
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector (1).
–Illustration shows the view with rear seat cushion and inspection
hole cover (RH) removed.
–: Vehicle front
3. Turn ignition switch ON.
4. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
1. Body ground M70 2. Body ground M16
PBIB2782E
PBIB2706E
Voltage: Approximately 5V
PBIB0932E

DTC P0181 FTT SENSOR
EC-1047
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Revision: 2007 April2007 M35/M45
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M66, B418

Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair open circuit or short to ground or short to power in harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “unified meter and A/C amp.” harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and “unified meter and
A/C amp.” terminal 58.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M66, B418

Harness for open or short between “fuel level sensor unit and fuel pump” and “unified meter and A/C
amp.”
>> Repair open circuit or short to ground or short to power in harness or connector.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-1048, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace “fuel level sensor unit and fuel pump”.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-857, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.

EC-1048
[VK45DE]
DTC P0181 FTT SENSOR
Revision: 2007 April2007 M35/M45
Component InspectionNBS005FM
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 4 and 5 by heating with hot water or heat gun as
shown in the figure.
Removal and InstallationNBS005FN
FUEL TANK TEMPERATURE SENSOR
Refer to FL-4, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
Temperature °C (°F) Resistance kΩ
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
PBIB0931E