2011 INFINITI QX56 Fuel

EC-280
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0191 FRP SENSOR
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK FRP SENSOR POWER SUPPLY-II
Check the voltage between FRP sensor harness connector and the ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK FRP SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
Check the continuity between ECM harness connector and the ground.
FRP sensor Voltag e
(Approx.)
Connector +
−
terminal
F26 1 3 5 V
+ −Voltag e
(Approx.)
FRP sensor
Connector Terminal F26 1 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Low fuel pressure sensor F25 3
Power steering pressure sensor F35 1
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 3 F111 40 Existed
Revision: 2010 May2011 QX56

P0191 FRP SENSOREC-281
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Is inspection result normal?
YES >> Check intermittent incident. Refer to
GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
6.CHECK FRP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK FRP SENSOR
Refer to EC-278, "
Component Inspection (Fuel Rail Pressure Sensor)".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (Fuel Rail Pressure Sensor)INFOID:0000000006288360
1.CHECK FRP SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “FUEL PRES SEN V” indication.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check FRP sensor signal voltage.
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 2 F111 31 Existed
Monitor Item Condition Values/Status
FUEL PRES SEN V Engine speed: Idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm
quickly
1,100 – 2,900 mV
Revision: 2010 May2011 QX56

P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208 INJECTOR
EC-287
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0201, P0202, P0203, P0204, P0205,
P0206, P0207, P0208 INJECTOR
DTC LogicINFOID:0000000006217835
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the foll owing procedure, comfirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start the engine and let it idle at least 30 seconds.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-287, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217836
1.PERFORM TROUBLE DIAGNOSIS FOR INJECTOR
Refer to EC-498, "
Component Function Check".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0201 No.1 fuel injector circuit ECM detects No. 1 injector circuit
is open or shorted.
 The fuel injector circuit is open or shorted
 Fuel injector
ECM
P0202 No. 2 fuel injector circuit
ECM detects No. 2 injector circuit
is open or shorted.
P0203 No. 3 fuel injector circuit ECM detects No. 3 injector circuit
is open or shorted.
P0204 No. 4 fuel injector circuit ECM detects No. 4 injector circuit
is open or shorted.
P0205 No. 5 fuel injector circuit ECM detects No. 5 injector circuit
is open or shorted.
P0206 No. 6 fuel injector circuit ECM detects No. 6 injector circuit
is open or shorted.
P0207 No. 7 fuel injector circuit ECM detects No. 7 injector circuit
is open or shorted.
P0208 No. 8 fuel injector circuit ECM detects No. 8 injector circuit
is open or shorted.
Revision: 2010 May2011 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-291
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P0300, P0301, P0302, P0303, P0304,
P0305, P0306, P0307, P0308 MIS-
FIRE
DTC LogicINFOID:0000000006217840
DTC DETECTION LOGIC
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor 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 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 in any one cylinder or in multiple cylinders.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Sensor Input signal to ECM ECM function
Crankshaft position sensor Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0300 MULTI CYL MISFIRE
(Multiple cylinder misfires detected) Multiple cylinders misfire.
 Improper spark plug
 Insufficient compression
 Incorrect fuel pressure
 The fuel injector circuit is open or shorted
 Fuel injector
 Intake air leakage
 The ignition signal circuit is open or shorted
 Lack of fuel
 Signal plate
 A/F sensor 1
 Incorrect PCV hose connection
P0301
CYL 1 MISFIRE
(No.1 cylinder misfire detected)
No. 1 cylinder misfires.
P0302 CYL 2 MISFIRE
(No. 2 cylinder misfire detected) No. 2 cylinder misfires.
P0303 CYL 3 MISFIRE
(No. 3 cylinder misfire detected) No. 3 cylinder misfires.
P0304 CYL 4 MISFIRE
(No. 4 cylinder misfire detected)
No. 4 cylinder misfires.
P0305 CYL 5 MISFIRE
(No. 5 cylinder misfire detected) No. 5 cylinder misfires.
P0306 CYL 6 MISFIRE
(No. 6 cylinder misfire detected) No. 6 cylinder misfires.
P0307 CYL 7 MISFIRE
(No. 7 cylinder misfire detected)
No. 7 cylinder misfires.
P0308 CYL 8 MISFIRE
(No. 8 cylinder misfire detected) No. 8 cylinder misfires.
Revision: 2010 May2011 QX56

EC-292
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
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.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and let it idle for about 15 minutes.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-292, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and drive the vehicle under 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.
Similar conditions to (1st trip) Freeze Frame Data mean that the following conditions should be satisfied at
the same time.
CAUTION:
Always drive vehicle in safe manner according to tr affic conditions and obey all traffic laws when
driving.
Driving time varies according to the engine speed in the freeze frame data.
5. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-292, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217841
1.CHECK FOR INTAKE AIR LEAKAGE AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leakage.
3. Check PCV hose connection.
Is intake air leakage detected?
YES >> Discover air leakage location and repair.
NO >> GO TO 2.
2.CHECK FOR EXHAUST SYSTEM CLOGGING
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)
Base fuel schedule Base fuel schedule in the freeze frame data × (1 ± 0.1)
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: 2010 May2011 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-293
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Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
Is the inspection result normal?
YES-1 >> With CONSULT-III: GO TO 3.
YES-2 >> Without CONSULT-III: GO TO 4.
NO >> Repair or replace malfunctioning part.
3.PERFORM POWER BALANCE TEST
WITH CONSULT-III
1. Start engine.
2. Perform “POWER BALANCE” in “A CTIVE TEST” mode with CONSULT-III.
3. Check that each circuit produces a momentary engine speed drop.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 4.
4.CHECK FUNCTION OF FUEL INJECTOR-I
1. Start engine and let it idle.
2. Listen to each fuel injector operation.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Perform trouble diagnosis for FUEL INJECTOR, refer to EC-498, "
Diagnosis Procedure".
5.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse No. in IPDM E/R to release fuel pressure. NOTE:
Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following pro-
cedure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical 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 (0.52 - 0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
 Never place the spark plug and the ignition coil within 50
cm (19.7 in) each other. Be careful not to get an electrical
shock while checking, becau se the electrical discharge
voltage becomes 20 kV or more.
 It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
NOTE:
Clicking sound should be heard.
PBIB3332E
Spark should be generated.
JMBIA0066GB
Revision: 2010 May2011 QX56

EC-294
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-506, "
Diagnosis Procedure".
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark Plug".
NO >> Repair or clean spark plug. Then GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark
Plug".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-16, "
Inspection".
Is the inspection result normal?
YES >> GO TO 10.
NO >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Check fuel pressure. Refer to EC-153, "
Work Procedure".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check fuel hoses and fuel tubes for clogging.
Is the inspection result normal?
Spark should be generated.
SEF156I
Spark should be generated.
Revision: 2010 May2011 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-295
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YES >> Replace “fuel filter and fuel pump assembly”.
NO >> Repair or replace malfunctioning part.
12.CHECK IDLE SPEED A
ND IGNITION TIMING
Check idle speed and ignition timing.
For procedure, refer to EC-530, "
Inspection" and EC-531, "Inspection".
For specification, refer to EC-538, "
Idle Speed" and EC-538, "Ignition Timing".
Is the inspection result normal?
YES >> GO TO 13.
NO >> Follow the EC-139, "
Work Procedure".
13.CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A /F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between A/F sensor 1 harness connector and ground.
Is the inspection result normal?
YES >> GO TO 14.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
14.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector
and ground.
5. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 15.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
15.CHECK A/F SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
DTCA/F sensor 1
Ground Voltage
Bank Connector Terminal
P0130 1 F67 4 Ground 3.0 V
P0150 2 F68 4
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Existed
P0150 2 F68 3 78
DTC A/F sensor 1 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Ground Not existed
P0150 2 F68 3 78
Revision: 2010 May2011 QX56