2007 INFINITI FX35 fuel pressure

EC-304
[VQ35DE]
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 July 2007 FX35/FX45
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicNBS003P4
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureNBS003P5
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes. The 1st trip DTC P0171 or P0174 should be detected at this
stage, if a malfunction exists. If so, go to EC-310, "
Diagnostic
Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 minutes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input signal to ECM ECM function Actuator
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection
control Fuel injector
DTC No.Trouble diagnosis
name DTC detecting condition Possible cause
P0171
0171
(Bank 1)
Fuel injection system
too lean

Fuel injection system does not operate properly.

The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.)

Intake air leaks

Air fuel ratio (A/F) sensor 1

Fuel injector

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Mass air flow sensor

Incorrect PCV hose connection
P0174
0174
(Bank 2)
SEF968Y
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)

EC-312
[VQ35DE]
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 July 2007 FX35/FX45
4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-85, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-86, "
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-636, "FUEL PUMP" .)

Fuel pressure regulator (Refer to EC-86, "FUEL PRESSURE CHECK" )

Fuel lines (Refer to FL-3, "Checking Fuel Lines" .)

Fuel filter for clogging
>> Repair or replace.
6. 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 Service $01 with GST.
OK or NG
OK (With CONSULT-II)>>GO TO 7.
OK (Without COUSULT-II)>>GO TO 8.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or ground. Refer to EC-187, "
DTC P0101 MAF SENSOR" .
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

EC-316
[VQ35DE]
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 July 2007 FX35/FX45
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTIONPFP:16600
On Board Diagnosis LogicNBS003P8
With the Air-Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the air fuel ratio (A/F) sensor 1. The
ECM calculates the necessary compensation to correct the offset between the actual and the theoretical
ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureNBS003P9
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. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes. The 1st trip DTC P0172, P0175 should be detected at this stage,
if a malfunction exists. If so, go to EC-322, "
Diagnostic Proce-
dure" .
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain time. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
Sensor Input signal to ECM ECM function Actuator
Air fuel ration (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection
control Fuel injector
DTC No.Trouble diagnosis
name DTC detecting condition Possible cause
P0172
0172
(Bank 1) Fuel injection system
too rich

Fuel injection system does not operate properly.

The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)

Air fuel ratio (A/F) sensor 1

Fuel injector

Exhaust gas leaks

Incorrect fuel pressure

Mass air flow sensor
P0175
0175
(Bank 2)
SEF968Y
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).

EC-324
[VQ35DE]
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
Revision: 2006 July 2007 FX35/FX45
4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-85, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-86, "
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-636, "FUEL PUMP" .)

Fuel pressure regulator (Refer to EC-86, "FUEL PRESSURE CHECK" .)
>> Repair or replace.
6. 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 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 ground. Refer to EC-187, "
DTC P0101 MAF SENSOR" .
7. CHECK FUNCTION OF FUEL INJECTOR
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.
OK or NG
OK >> GO TO 10.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-629, "
FUEL INJECTOR" .
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

DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS- FIRE
EC-345
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis LogicNBS003PY
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage) On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration) For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300 Multiple cylinder misfire
detected Multiple cylinder misfire.

Improper spark plug

Insufficient compression

Incorrect fuel pressure

Fuel injector circuit is open or shorted

Fuel injector

Intake air leak

Ignition signal circuit is open or shorted

Lack of fuel

Signal plate

Air fuel ratio (A/F) sensor 1

Incorrect PCV hose connection
P0301
0301 No.1 cylinder misfire
detected No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected No. 4 cylinder misfires.
P0305
0305 No. 5 cylinder misfire
detected No. 5 cylinder misfires.
P0306
0306 No. 6 cylinder misfire
detected No. 6 cylinder misfires.

EC-350
[VQ35DE]
DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS- FIRE
Revision: 2006 July 2007 FX35/FX45
6. CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Remove fuel pump fuse in IPDM E/R to release fuel pressure. NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
4. Start engine.
5. After engine stalls, crank it two or three times to release all fuel pressure.
6. Turn ignition switch OFF.
7. Remove all ignition coil harness connectors to avoid the electri- cal discharge from the ignition coils.
8. Remove ignition coil and spark plug of the cylinder to be checked.
9. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
10. Connect spark plug and harness connector to ignition coil.
11. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion
as shown in the figure.
12. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal por-
tion.
CAUTION:

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.

It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 10.
NG >> GO TO 7.
7. CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
OK or NG
OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-650, "
IGNITION SIGNAL" .
Spark should be generated.
PBIB1603E
PBIB2325E
Spark should be generated.

DTC P0300 - P0306 MULTIPLE CYLINDER MISFIRE, NO. 1 - 6 CYLINDER MIS- FIRE
EC-351
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
8. CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-20, "
Changing Spark Plugs
(Platinum-Tipped Type)" .
NG >> 1. Repair or clean spark plug.
2. GO TO 9.
9. CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.
OK or NG
OK >> INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-20, "
Changing
Spark Plugs (Platinum-Tipped Type)" .
10. CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-101, "
CHECKING COMPRESSION PRESSURE" .
OK or NG
OK >> GO TO 11.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
11 . CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-85, "
FUEL PRESSURE RELEASE" .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-86, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 13.
NG >> GO TO 12.
12. DETECT MALFUNCTIONING PART
Check the following.

Fuel pump and circuit (Refer to EC-636, "FUEL PUMP" .)

Fuel pressure regulator (Refer to EC-86, "FUEL PRESSURE CHECK" .)

Fuel lines (Refer to MA-17, "Checking Fuel Lines" .)

Fuel filter for clogging
>> Repair or replace.
SEF156I
Spark should be generated.
At idle: Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)

DTC P0420, P0430 THREE WAY CATALYST FUNCTION EC-379
[VQ35DE]
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Revision: 2006 July 2007 FX35/FX45
5. CHECK FUEL INJECTOR
1. Stop engine and then turn ignition switch ON.
2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42 and ground with CONSULT-II or tester.
Refer to Wiring Diagram for fuel injector, EC-630, "
Wiring Dia-
gram" .
OK or NG
OK >> GO TO 6.
NG >> Perform EC-631, "
Diagnostic Procedure" .
6. CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Reconnect ECM harness connector disconnected.
3. Remove fuel pump fuse in IPDM E/R to release fuel pressure. NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
4. Start engine.
5. After engine stalls, crank it two or three times to release all fuel pressure.
6. Turn ignition switch OFF.
7. Remove all ignition coil harness connectors to avoid the electri- cal discharge from the ignition coils.
8. Remove ignition coil and spark plug of the cylinder to be checked.
9. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
10. Connect spark plug and harness connector to ignition coil.
11. Fix ignition coil using a rope etc. with gap of 13 - 17 mm between the edge of the spark plug and grounded metal portion
as shown in the figure.
12. Crank engine for about 3 seconds, and check whether spark is generated between the spark plug and the grounded metal por-
tion.
CAUTION:

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.

It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 10.
NG >> GO TO 7. Voltage: Battery voltage
PBIB2250E
Spark should be generated.
PBIB1603E
PBIB2325E