2009 INFINITI QX56 fuel

EC-184
< COMPONENT DIAGNOSIS >[VK56DE]
P0182, P0183 FTT SENSOR
>>
INSPECTION END
Component InspectionINFOID:0000000003771448
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 3 and 4 by heating with hot water as shown in the fig-
ure.
If NG, replace fuel level sensor unit.
Temperature °C ( °F)] Resistance (k Ω)
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
SEF476YA
Revision: December 20092009 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-189
< COMPONENT DIAGNOSIS > [VK56DE]
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EC
NP
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P0300, P0301, P0302, P0303, P0304,
P0305, P0306, P0307, P0308 MIS-
FIRE
On Board Diagnosis LogicINFOID:0000000003771454
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, when a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, 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 t hat 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 t hat 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. Du ring 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.
DTC Confirmation ProcedureINFOID:0000000003771455
CAUTION:
Always drive vehicle in safe manner according to traf fic conditions and obey all traffic laws when driv-
ing.
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.
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
 The injector circuit is open or shorted
 Fuel injector
 Intake air leak
 The ignition signal circuit is open or short-ed
 Lack of fuel
 Signal plate
 Air fuel ratio (A/F) sensor 1
 Incorrect PCV hose connection
P0301
0301
No.1 cylinder misfire de-
tected
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.
P0307
0307 No. 7 cylinder misfire
detected
No. 7 cylinder misfires.
P0308
0308 No. 8 cylinder misfire
detected
No. 8 cylinder misfires.
Revision: December 20092009 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-191
< COMPONENT DIAGNOSIS > [VK56DE]
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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
< COMPONENT DIAGNOSIS >[VK56DE]
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

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-193
< COMPONENT DIAGNOSIS > [VK56DE]
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OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .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"
.)
 Fuel lines
 Fuel filter for clogging
>> Repair or replace.
12.CHECK IGNITION TIMING
Check the following items. Refer to EC-13, "Basic Inspection"
.
OK or NG
OK >> GO TO 13.
NG >> Follow the EC-13, "Basic Inspection"
.
13.CHECK A/F SENSOR 1 INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect 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.
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
A/F sensor 1 terminal ECM terminal
Bank 1 135
256
Bank 2 116
275
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 135116
256275
BBIA0376E
Revision: December 20092009 QX56

EC-194
< COMPONENT DIAGNOSIS >[VK56DE]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
6. Also check harness for short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14.CHECK A/F SENSOR 1 HEATER
Refer to EC-96, "Component Inspection"
.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
CAUTION:
 Discard any air fuel ratio (A/F) sensor which has b een dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
 Before installing new ai r fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sensor
Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
16.CHECK MASS AIR FLOW SENSOR
With CONSULT-III
Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-III.
With GST
Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 17.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-103
.
17.CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-475, "Symptom Matrix Chart"
.
OK or NG
OK >> GO TO 18.
NG >> Repair or replace.
18.ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memo ry after performing the tests. Refer to EC-456, "DTC Index"
.
>> GO TO 19.
19.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Continuity should not exist.
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
Revision: December 20092009 QX56

EC-206
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE
WAY CATALYST FUNCTION
P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000003771472
The ECM monitors the switching frequency ratio of air fuel sensor
(A/F) sensor 1 and heat ed oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decr eases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specif ied limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000003771473
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.
WITH CONSULT-III
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “C OOLAN TEMP/S” indication reaches to 70°C (158 °F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “S RT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to “CMPLT” (It
will take approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70 °C (158 °F) and then retest from step 1.
12. Select “SELF-DIAG RESULTS” mode with CONSULT-III.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1) Catalyst system efficien-
cy below threshold  Three way catalyst (manifold) does not oper-
ate properly.
 Three way catalyst (manifold) does not have enough oxygen storage capacity.  Three way catalyst (manifold)
 Exhaust tube
 Intake air leaks
 Fuel injector
 Fuel injector leaks
 Spark plug
 Improper ignition timing
P0430
0430
(Bank 2)
Revision: December 20092009 QX56

EC-208
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE
WAY CATALYST FUNCTION
Check the following items. Refer to EC-13, "Basic Inspection".
OK or NG
OK >> GO TO 5.
NG >> Follow the EC-13, "Basic Inspection"
.
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, 44, 63 and ground with CONSULT-III or tester.
Refer to Wiring Diagram for fuel injector, EC-432, "Wiring Dia-
gram - ENGINE CONTROL SYSTEM -".
OK or NG
OK >> GO TO 6.
NG >> Perform EC-404, "Diagnosis 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. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-III to releas e 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:
 Do not approach to the spar k plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the el ectrical 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
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
Battery voltage should exist.
PBIB1527E
Spark should be generated.
BBIA0380E
PBIB2325E
Revision: December 20092009 QX56