2006 INFINITI QX56 engine

DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-FIRE
EC-331
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Revision: November 2009 2006 QX56
7. 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 EM-29, "
SPARK PLUG (PLATI-
NUM-TIPPED TYPE)" .
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 spark plug(s) with standard type one(s). For spark plug type, refer to MA-18, "
Changing
Spark Plugs" .
9. CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-63, "
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-80, "
FUEL PRESSURE RELEASE" .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-82, "
FUEL PRESSURE CHECK" .
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-604, "FUEL PUMP" .)

Fuel pressure regulator (Refer to EC-82, "FUEL PRESSURE CHECK" .)

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 P0327, P0328, P0332, P0333 KSEC-335
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Revision: November 2009 2006 QX56
DTC P0327, P0328, P0332, P0333 KSPFP:22060
Component DescriptionUBS00H3T
The knock sensor is attached to the 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 Diagnosis LogicUBS00H3U
The MIL will not light up for these diagnoses.
DTC Confirmation ProcedureUBS00H3V
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-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and run it for at least 5 seconds at idle speed.
3. If 1st trip DTC is detected, go to EC-337, "
Diagnostic Procedure"
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0021E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0327
0327
(bank 1) Knock sensor circuit low
input 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
input An excessively high voltage from the sensor
is sent to ECM.
P0333
0333
(bank 2)
SEF058Y

DTC P0327, P0328, P0332, P0333 KSEC-337
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Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00H3X
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.
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-339, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace knock sensor.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
15
36 W
W Knock sensor (bank 1)
Knock sensor (bank 2) [Engine is running]

Idle speed
Approximately 2.5V
Resistance: Approximately 532 - 588 kΩ
[at 20°C (68 °F)]
Continuity should exist.
PBIB0021E

EC-340Revision: November 2009
DTC P0335 CKP SENSOR (POS)
2006 QX56
DTC P0335 CKP SENSOR (POS)PFP:23731
Component DescriptionUBS00H40
The crankshaft position sensor (POS) 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.
CONSULT-II Reference Value in Data Monitor ModeUBS00H41
Specification data are reference values.
On Board Diagnosis LogicUBS00H42
DTC Confirmation ProcedureUBS00H43
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 10.5V with igni-
tion switch ON.
PBIB0562E
PBIB2448E
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED

Run engine and compare CONSULT-II value with the tachometer indication. Almost the same speed as the
tachometer indication.
DTC No. Trouble diagnosis name
DTC detecting condition Possible cause
P0335
0335 Crankshaft position
sensor (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
running.

Harness or connectors
(The sensor circuit is open or shorted)

Crankshaft position sensor (POS)

Signal plate

DTC P0335 CKP SENSOR (POS)EC-341
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Revision: November 2009 2006 QX56
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Crank engine for at least 2 seconds and run it for at least 5 sec- onds at idle speed.
3. If 1st trip DTC is detected, go to EC-343, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

DTC P0335 CKP SENSOR (POS)EC-343
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Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00H45
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
13 O Crankshaft position sensor
(POS) [Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle. 1.0 - 2.0V
[Engine is running]

Engine speed: 2,000 rpm. 1.0 - 2.0V
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition switch
OFF
0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning ignition
switch OFF BATTERY VOLTAGE
(11 - 14V)
11 9
120 BR
BR
Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
PBIB1041E
PBIB1042E
BBIA0354E

DTC P0340 CMP SENSOR (PHASE)EC-347
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Revision: November 2009 2006 QX56
DTC P0340 CMP SENSOR (PHASE)PFP:23731
Component DescriptionUBS00H48
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 LogicUBS00H49
DTC Confirmation ProcedureUBS00H4A
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 10.5V with igni-
tion switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
PBIB0562E
PBIB2448E
DTC No. Trouble diagnosis nameDTC 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
SC-10, "START-
ING SYSTEM" .)

Starting system circuit (Refer to SC-10,
"STARTING SYSTEM" .)

Dead (Weak) battery

EC-348Revision: November 2009
DTC P0340 CMP SENSOR (PHASE)
2006 QX56
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. Crank engine for at least 2 seconds and run it for at least 5 sec- onds at idle speed.
4. If 1st trip DTC is detected, go to EC-350, "
Diagnostic 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. If 1st trip DTC is detected, go to EC-350, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y