2010 INFINITI QX56 ecm

P0327, P0328, P0332, P0333 KSEC-199
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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-200, "
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-85, "
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.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7. Continuity should exist.
PBIB0021E
BBIA0354E
Continuity should exist.
Revision: April 20092010 QX56

P0335 CKP SENSOR (POS)EC-201
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P0335 CKP SENSOR (POS)
Component DescriptionINFOID:0000000005149219
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:0000000005149220
DTC Confirmation ProcedureINFOID:0000000005149221
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 follo wing procedure, confirm that battery vo ltage is more than 10.5 V 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-201, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149222
1.CHECK GROUND CONNECTIONS
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: April 20092010 QX56

EC-202
< COMPONENT DIAGNOSIS >[VK56DE]
P0335 CKP SENSOR (POS)
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 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.
3. Also check harness for short to power.
OK or NG
BBIA0354E
BBIA0367E
Voltage: Battery voltage
SEF481Y
Continuity should exist.
Revision: April 20092010 QX56

P0335 CKP SENSOR (POS)EC-203
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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-203, "
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:0000000005149223
CRANKSHAFT POSITION SENSOR (POS)
1. Loosen the fixing bolt of the sensor.
2. Disconnect crankshaft position sensor (POS) harness connector.
3. Remove the sensor.
4. Visually check the sensor for chipping. Continuity should exist.
PBIB0563E
Revision: April 20092010 QX56

P0340 CMP SENSOR (PHASE)EC-205
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P0340 CMP SENSOR (PHASE)
Component DescriptionINFOID:0000000005149224
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:0000000005149225
DTC Confirmation ProcedureINFOID:0000000005149226
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 following procedure, confirm th at 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-206, "
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-206, "
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-19
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• Starting system ci rcuit (Refer to STR-19
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• Dead (Weak) battery
Revision: April 20092010 QX56

P0340 CMP SENSOR (PHASE)EC-207
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• Harness for open or short between camshaft position sensor (PHASE) and ECM
• Harness for open or short between camshaft
position sensor (PHASE) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK CMP SENSOR (PHASE) GRO UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CMP sensor (PHASE) terminal 1 and ground. Refer to wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short betw een CMP sensor (PHASE) and ground
>> Repair open circuit or short to power in harness or connectors.
7.CHECK CMP SENSOR (PHASE) INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM termi nal 14 and CMP sensor (PHASE) terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK CAMSHAFT POSITI ON SENSOR (PHASE)
Refer to EC-207, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace camshaft position sensor (PHASE).
9.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000005149228
CAMSHAFT POSITION SENSOR (PHASE)
1. Loosen the fixing bolt of the sensor.
2. Disconnect camshaft position s ensor (PHASE) harness connector.
3. Remove the sensor. Continuity should exist.
Continuity should exist.
Revision: April 20092010 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-209
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P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000005149229
The ECM monitors the switching
frequency ratio of air fuel sensor
(A/F) sensor 1 and heated 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 decreases, 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 specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000005149230
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.
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 “COOLAN TEMP/S” indication reaches to 70°C (158° F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT 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 unt il “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 RESU LTS” 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: April 20092010 QX56

EC-210
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE WAY CATALYST FUNCTION
13. Confirm that the 1st trip DTC is not detected.
If the 1st trip DTC is detected, go to EC-210, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000005149231
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-210, "
Diagnosis Procedure".
• 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
Diagnosis ProcedureINFOID:0000000005149232
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: April 20092010 QX56