INFINITI QX56 2008 Factory Service Manual

EC-202
< COMPONENT DIAGNOSIS >[VK56DE]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
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-402, "
Diagnosis Procedure".)
• Fuel pressure regulator (Refer to EC-494, "
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 13
5
25 6
Bank 2 11
6
27 5
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 13 511 6
25 627 5
BBIA0376E
Revision: March 2010 2008 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-203
< COMPONENT DIAGNOSIS > [VK56DE]
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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-99, "
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 f uel 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 air fuel ra tio (A/F) sensor, clean exhaust syst em 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-106
.
17.CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-481, "
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 memory after performing the tests. Refer to EC-462, "
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: March 2010
2008 QX56

EC-204
< COMPONENT DIAGNOSIS >[VK56DE]
P0327, P0328,
P0332, P0333 KS
P0327, P0328, P0332, P0333 KS
Component DescriptionINFOID:0000000001351546
The knock sensor is attached to t he cylinder block. It senses engine
knocking using a piezoelectric element. 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 Diagn osis LogicINFOID:0000000001351547
The MIL will not light up for these self-diagnoses.
DTC Confirmation ProcedureINFOID:0000000001351548
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-III
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-204, "
Diagnosis Procedure"
With GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351550
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 conditionPossible 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)
Revision: March 2010 2008 QX56

P0327, P0328, P0332, P0333 KSEC-205
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2.CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect knock sensor harness connector.
2. Check harness continuity between ECM terminal 15 and knock sensor (bank1) terminal 1, ECM terminal 36 and knock sensor
(bank 2) terminal 1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F26, F101
• Harness for open or short between ECM and knock sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK KNOCK SENSOR
Refer to EC-206, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning knock sensor.
5.CHECK GROUND CONNECTIONS
Loosen and retighten three ground screws on the body.
Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 6.
NG >> Repair or replace ground connections.
6.CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Disconnect knock sensor harness connector.
2. Check harness continuity between knock sensor terminal 2 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power. Resistance: Approximately 532 - 588 k
Ω [at 20 °C (68° F)]
Continuity should exist.
PBIB0021E
BBIA0354E
Continuity should exist.
Revision: March 2010 2008 QX56

EC-206
< COMPONENT DIAGNOSIS >[VK56DE]
P0327, P0328,
P0332, P0333 KS
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F26, F101
• Harness connectors F14, E5
• Harness for open or short between knock sensor terminal 2 and ground
>> Repair open circuit or short power in harness or connectors.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351551
KNOCK SENSOR
Check resistance between knock sensor terminal 1 and ground.
NOTE:
It is necessary to use an ohmmeter which can measure more
than 10 M Ω.
CAUTION:
Do not use any knock sensors th at have been dropped or phys-
ically damaged. Use only new ones. Resistance: Approximately 532 - 588 k
Ω [at 20° C (68°F)]
SEF227W
Revision: March 2010 2008 QX56

P0335 CKP SENSOR (POS)EC-207
< COMPONENT DIAGNOSIS > [VK56DE]
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P0335 CKP SENSOR (POS)
Component DescriptionINFOID:0000000001351553
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 fiel d, 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 Diagnosis LogicINFOID:0000000001351555
DTC Confirmation ProcedureINFOID:0000000001351556
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.
TESTING CONDITION:
Before performing the following procedure, confirm th at battery voltage is more than 10.5V with igni-
tion switch ON.
WITH CONSULT-III
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-208, "
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: March 2010 2008 QX56

EC-208
< COMPONENT DIAGNOSIS >[VK56DE]
P0335 CKP SENSOR (POS)
Diagnosis Procedure
INFOID:0000000001351558
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK CRANKSHAFT POSITION (CKP) SE NSOR (POS) POWER SUPPLY CIRCUIT
1. Disconnect crankshaft position (CKP) sensor (POS) harness connector.
2. Turn ignition switch ON.
3. Check voltage between CKP sensor (POS) terminal 3 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short between cran kshaft position sensor (POS) and ECM
• Harness for open or short between crankshaf t position sensor (POS) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK CKP SENSOR (POS) GRO UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CK P sensor (POS) terminal 1 and ground.
Refer to Wiring Diagram.
BBIA0354E
BBIA0367E
Voltage: Battery voltage
SEF481Y
Revision: March 2010 2008 QX56

P0335 CKP SENSOR (POS)EC-209
< COMPONENT DIAGNOSIS > [VK56DE]
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3. Also check harness for short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short between crank shaft position sensor (POS) and ground
>> Repair open circuit or short to power in harness or connectors.
6.CHECK CKP SENSOR (POS) INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 13 and CKP sensor (POS) terminal 2. Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to EC-209, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace crankshaft position sensor (POS).
8.CHECK GEAR TOOTH
Visually check for chipping signal plate gear tooth.
OK or NG
OK >> GO TO 9.
NG >> Replace the signal plate.
9.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351559
CRANKSHAFT POSITION SENSOR (POS)
1. Loosen the fixing bolt of the sensor.
2. Disconnect crankshaft position sensor (POS) harness connector.
3. Remove the sensor. Continuity should exist.
Continuity should exist.
Revision: March 2010
2008 QX56

EC-210
< COMPONENT DIAGNOSIS >[VK56DE]
P0335 CKP SENSOR (POS)
4. Visually check the sensor for chipping.
5. Check resistance as shown in the figure.
PBIB0563E
Terminal No. (Polarity)
Resistance Ω [at 25 °C (77 °F)]
1 (+) - 2 (-) Except 0 or ∞
1 (+) - 3 (-)
2 (+) - 3 (-)
PBIB0564E
Revision: March 2010 2008 QX56

P0340 CMP SENSOR (PHASE)EC-211
< COMPONENT DIAGNOSIS > [VK56DE]
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P0340 CMP SENSOR (PHASE)
Component DescriptionINFOID:0000000001351561
The camshaft position sensor (PHASE) senses the protrusion of
exhaust valve cam sprocket to identify a particular cylinder. The
camshaft position sensor (PHASE) senses the piston position.
When the crankshaft position sensor (POS) system becomes inoper-
ative, the camshaft position sensor
(PHASE) provides various con-
trols of engine parts instead, utilizing timing of cylinder identification
signals.
The sensor consists of a permanent magnet and Hall IC.
When 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.
ECM receives the signals as shown in the figure.
On Board Diagnosis LogicINFOID:0000000001351562
DTC Confirmation ProcedureINFOID:0000000001351563
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.
TESTING CONDITION:
Before performing the following procedure, confirm th at battery voltage is more than 10.5V with igni-
tion switch ON.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Crank engine for at least 2 seconds and run it for at least 5 seconds at idle speed.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-212, "
Diagnosis Procedure".
If 1st trip DTC is not detected, go to next step.
5. Maintaining engine speed at more than 800 rpm for at least 5 seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-212, "
Diagnosis Procedure".
PBIB0562E
PBIB3459E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0340
0340 Camshaft position sen-
sor (PHASE) circuit • The cylinder No. signal is not sent to ECM for
the first few seconds during engine cranking.
• The cylinder No. signal is not sent to ECM during engine running.
• The cylinder No. signal is not in the normal
pattern during engine running. • Harness or connectors
(The sensor circuit is open or shorted)
• Camshaft position sensor (PHASE)
• Camshaft (Exhaust)
• Starter motor (Refer to STR-17
.)
• Starting system ci rcuit (Refer to STR-17
.)
• Dead (Weak) battery
Revision: March 2010 2008 QX56