2009 INFINITI QX56 engine

P0327, P0328, P0332, P0333 KS
EC-195
< COMPONENT DIAGNOSIS > [VK56DE]
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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
< COMPONENT DIAGNOSIS >[VK56DE]
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

EC-202
< COMPONENT DIAGNOSIS >[VK56DE]
P0340 CMP SENSOR (PHASE)
P0340 CMP SENSOR (PHASE)
Component DescriptionINFOID:0000000003771467
The camshaft position sensor (P
HASE) 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, utilizi ng 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 Diagn osis LogicINFOID:0000000003771468
DTC Confirmation ProcedureINFOID:0000000003771469
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. 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-203, "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-203, "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-18
.)
 Starting system circuit (Refer to STR-18
.)
 Dead (Weak) battery
Revision: December 20092009 QX56

P0340 CMP SENSOR (PHASE)EC-203
< COMPONENT DIAGNOSIS > [VK56DE]
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Diagnosis ProcedureINFOID:0000000003771470
1.CHECK STARTING SYSTEM
Turn ignition switch to START position.
Ye s o r N o
Yes >> GO TO 2.
No >> Check starting system. (Refer to STR-18
.)
2.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3.CHECK CAMSHAFT POSITION (CMP) SEN SOR (PHASE) POWER SUPPLY CIRCUIT
1. Disconnect camshaft position (C MP) sensor (PHASE) (2) har-
ness connector.
- Radiator hose (1)
2. Turn ignition switch ON.
3. Check voltage between CMP sensor (PHASE) terminal 3 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors F32, E2 Does the engine turn over?
Does the starter motor operate?
BBIA0354E
BBIA0740E
Voltage: Battery voltage
SEF481Y
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

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-207
< COMPONENT DIAGNOSIS > [VK56DE]
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13. Confirm that the 1st trip DTC is not detected.
If the 1st trip DTC is detected, go to EC-207, "Diagnosis Procedure"
.
Overall Function CheckINFOID:0000000003771474
Use this procedure to check the overall function of the th ree way catalyst (manifold). During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Set voltmeter probes between ECM terminals ECM terminals 55 [HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) signal] and
ground.
7. Keep engine speed at 2,500 rpm constant under no load.
8. Make sure that the voltage does not vary for more than 5 sec- onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to
EC-207, "Diagnosis Procedure"
.
 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
Diagnosis ProcedureINFOID:0000000003771475
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK IGNITION TIMING
PBIB2056E
PBIB1216E
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

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-209
< COMPONENT DIAGNOSIS > [VK56DE]
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OK >> GO TO 10.
NG >> GO TO 7.
7.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 whet her spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-404, "Diagnosis Procedure"
.
8.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 9.
9.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about three 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".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly. Refer to EM-40, "Removal and Installation"
.
Keep fuel hose and all fuel injectors connected to fuel injector gallery.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON. Make sure fuel does not drip from fuel injector.
OK or NG
OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the fuel injector(s) from which fuel is dripping.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
Trouble is fixed.>> INSPECTION END
Trouble is not fixed.>>Replace three way catalyst assembly. Spark should be generated.
SEF156I
Spark should be generated.
Revision: December 20092009 QX56