check engine INFINITI QX56 2009 Factory Service Manual

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-177
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OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-487, "Fuel Pressure Check"
.
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-487, "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-395, "Diagnosis Procedure"
.)
 Fuel pressure regulator (Refer to EC-487, "Fuel Pressure Check"
.)
>> Repair or replace.
6.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-III.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose c onnections in the mass air flow sensor circuit or
grounds. Refer to EC-103
.
7.CHECK FUNCTION OF FUEL INJECTOR
With CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-III
1. Start engine. At idling: Approximately 350 kPa (3.57 kg/cm
2, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
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EC-178
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P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
2. Listen to each fuel injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for FUEL INJECTOR, refer to
EC-392, "Diagnosis Procedure"
.
8.CHECK FUEL INJECTOR
1. Remove fuel injector assembly. Refer to EM-40, "Removal and Installation"
.
Keep fuel hose and all fuel injectors connected to fuel injector gallery.
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 9.
NG (Drips.)>>Replace the fuel injectors from which fuel is dripping. Always replace O-ring with new one.
9.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Clicking noise should be heard.
PBIB1986E
Revision: December 20092009 QX56

P0181 FTT SENSOREC-179
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P0181 FTT SENSOR
Component DescriptionINFOID:0000000003771439
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 ther mistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: 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 te rminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000003771440
DTC Confirmation ProcedureINFOID:0000000003771441
1. If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 10 seconds.
3. Check 1st trip DTC. If 1st trip DTC is detected, go to EC-180, "Diagnosis Procedure"
.
If 1st trip DTC is not detected, go to following step.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check “COOLAN TEMP/S” value. If the “COOLAN TEMP/S” is less than 60 °C (140 °F), the result will be OK.
If the “COOLAN TEMP/S” is above 60 °C (140 °F), go to the following step.
6. Cool engine down until “COOLAN TEMP/S” signal is less than 60 °C (140 °F).
7. Wait at least 10 seconds.
8. Check 1st trip DTC.
BBIA0583E
Fluid temperature °C ( °F)] Voltage*
(V) Resistance
(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
0181 Fuel tank temperature
sensor circuit range/per-
formance Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signals
from engine coolant temperature sensor and in-
take air temperature sensor.
 Harness or connectors
(The sensor circuit is open or shorted)
 Fuel tank temperature sensor
Revision: December 20092009 QX56

P0222, P0223 APP SENSOREC-185
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P0222, P0223 APP SENSOR
Component DescriptionINFOID:0000000003771449
Electric throttle control actuator
consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has t he two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect t he opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagnosis LogicINFOID:0000000003771450
These self-diagnoses have the on e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003771451
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-185, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771452
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0222
0222 Throttle position sensor
1 circuit low input An excessively low voltage from the TP sensor
1 is sent to ECM.  Harness or connectors
(TP sensor 1 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
 Electric throttle control actuator
(TP sensor 1)
 Accelerator pedal position sensor (APP sensor 2)
P0223
0223
Throttle position sensor
1 circuit high input An excessively high voltage from the TP sensor
1 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
Revision: December 20092009 QX56

EC-186
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P0222, P0223 APP SENSOR
Refer to
EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK THROTTLE POSITION SE NSOR 1 POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator (1) harness connec- tor.
- Illustration shows the view with intake air duct removed.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal 2 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK THROTTLE POSITION SE NSOR 1 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit.
4.CHECK THROTTLE POSITION SENS OR 1 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
BBIA0354E
BBIA0371E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-432, "Wiring Diagram - ENGINE
CONTROL SYSTEM -"91 APP sensor terminal 6
Revision: December 20092009 QX56

EC-190
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P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
3. Turn ignition swich OFF and wait at least 10 seconds.
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Restart engine and let it idle for about 15 minutes.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-190, "Diagnosis Procedure"
.
NOTE:
If 1st trip DTC is not detected during above proc edure, performing 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 conditi ons 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 Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
The time to driving varies according to the engine speed in the freeze frame data.
Diagnosis ProcedureINFOID:0000000003771456
1.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2.CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace it.
3.PERFORM POWER BALANCE TEST
With CONSULT-III
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT-III
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).
Engine speed Time
Around 1,000 rpm Approximately 10 minutes
Around 2,000 rpm Approximately 5 minutes
More than 3,000 rpm Approximately 3.5 minutes
Revision: December 20092009 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-191
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When disconnecting each fuel injector harness connector
one at a time, is there any cylinder which does not
produce a momentary engine speed drop?
Ye s o r N o
Yes >> GO TO 4.
No >> GO TO 7.
4.CHECK FUEL INJECTOR
Does each fuel injector make an operating sound at idle?
Ye s o r N o
Yes >> GO TO 5.
No >> Check fuel injector(s) and circuit(s). Refer to EC-392,
"Diagnosis Procedure".
5.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. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri- cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. 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.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
BBIA0374E
PBIB1986E
Spark should be generated.
BBIA0380E
PBIB2325E
Revision: December 20092009 QX56

EC-192
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P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
 Do not approach to the spark pl ug 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 9.
NG >> GO TO 6.
6.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 7.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-404, "Diagnosis Procedure"
.
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to EM-16, "Removal
and Installation".
NG >> 1. Repair or clean spark plug.
2. GO TO 8.
8.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 malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to EM-
16, "Removal and Installation".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-23, "Checking Compression Pressure"
.
OK or NG
OK >> GO TO 10.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-487, "Fuel Pressure Check"
.
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-487, "Fuel Pressure Check"
.
Spark should be generated.
SEF156I
Spark should be generated.
At idling: Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
Revision: December 20092009 QX56

P0327, P0328, P0332, P0333 KS
EC-195
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P0327, P0328, P0332, P0333 KS
Component DescriptionINFOID:0000000003771457
The knock sensor is attached to t
he cylinder block. It senses engine
knocking using a piezoelectric el ement. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
On Board Diagnosis LogicINFOID:0000000003771458
The MIL will not light up for these self-diagnoses.
DTC Confirmation ProcedureINFOID:0000000003771459
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1. Start engine and run it for at least 5 seconds at idle speed.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-195, "Diagnosis Procedure"
Diagnosis ProcedureINFOID:0000000003771460
1.CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminals 15, 36 and ground. Refer to Wiring Diagram. NOTE:
It is necessary to use an ohmmeter which can measure more than 10 M Ω.
PBIB0021E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0327
0327
(bank 1) Knock sensor circuit low in-
put An excessively low voltage from the sensor
is sent to ECM.
 Harness or connectors(The sensor circuit is open or shorted.)
 Knock sensor
P0332
0332
(bank 2)
P0328
0328
(bank 1)
Knock sensor circuit high in-
put An excessively high voltage from the sensor
is sent to ECM.
P0333
0333
(bank 2)
Resistance: Approximately 532 - 588 k Ω [at 20 °C (68 °F)]
Revision: December 20092009 QX56

EC-198
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P0335 CKP SENSOR (POS)
P0335 CKP SENSOR (POS)
Component DescriptionINFOID:0000000003771462
The crankshaft position sensor (P
OS) is located on the A/T assem-
bly facing the gear teeth (cogs) of the signal plate. It detects the fluc-
tuation of the engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
On Board Diagn osis LogicINFOID:0000000003771463
DTC Confirmation ProcedureINFOID:0000000003771464
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following pro cedure, confirm that battery voltage is more than 10.5V with igni-
tion switch ON.
1. Crank engine for at least 2 seconds and run it for at least 5 seconds at idle speed.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-199, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-III” above.
PBIB0562E
PBIB3459E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0335
0335 Crankshaft position sen-
sor (POS) circuit  The crankshaft position sensor (POS) signal
is not detected by the ECM during the first
few seconds of engine cranking.
 The proper pulse signal from the crankshaft position sensor (POS) is not sent to ECM
while the engine is running.
 The crankshaft position sensor (POS) signal is not in the normal pattern during engine run-
ning.  Harness or connectors
(The sensor circuit is open or shorted)
 Crankshaft position sensor (POS)
 Signal plate
Revision: December 20092009 QX56