2011 INFINITI QX56 ECU

VVEL CONTROL MODULEEC-113
< ECU DIAGNOSIS INFORMATION > [VK56VD]
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.) 25
(L/B) 14
(B) VVEL control motor
(Low lift) (bank 1)
Output[Engine is running]
 Warm-up condition
 Idle speed
0 - 14 V
[Engine is running]
 Warm-up condition
 When revving engine up to 3,000 rpm quickly 0 - 14 V
Terminal No. Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
JMBIA0854ZZ
JMBIA0855ZZ
Revision: 2010 May2011 QX56

P0011, P0021 IVT CONTROLEC-177
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0011, P0021 IVT CONTROL
DTC LogicINFOID:0000000006217772
DTC DETECTION LOGIC
NOTE:
If DTC P0011 or P0021 is displayed with DTC P0075
or P0081, first perform the trouble diagnosis for
DTC P0075, P0081. Refer to EC-193, "
DTC 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 following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
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. Maintain the following conditions for at least 6 consecutive seconds. Hold the accelerator pedal as steady as possible.
4. Let engine idle for 25 seconds.
5. Check 1st trip DTC. WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-178, "Diagnosis Procedure"
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
WITH CONSULT-III
1. Select “DATA MONITOR” mode with CONSULT-III.
2. Maintain the following conditions for at least 20 consecutive seconds.
DTC No. Trouble diagnosis
(Trouble diagnosis con- tent) Detecting condition Possible cause
P0011 INT/V TIM CONT-B1
[Intake valve timing control
performance (bank 1)]
There is a gap between angle of target
and phase-control angle degree.  Crankshaft position sensor
 Camshaft position sensor
 Intake valve timing control solenoid valve
 Accumulation of debris to the signal pick-up
portion of the camshaft
 Timing chain installation
 Foreign matter caught in the oil groove for in- take valve timing control
P0021
INT/V TIM CONT-B2
[Intake valve timing control
performance (bank 2)]
ENG SPEED Less than 2,000 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70
°C (158 °F)
Selector lever P or N position
ENG SPEED 1,500 - 3,175 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70 °C (158 °F)
Revision: 2010 May2011 QX56

EC-224
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0127 IAT SENSOR
P0127 IAT SENSOR
DTC LogicINFOID:0000000006288283
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:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Wait until engine coolant temperature is less than 90 °C (194 °F)
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT-III.
- Check the engine coolant temperature.
- If the engine coolant temperature is not less than 90 °C (194 °F), turn ignition switch OFF and cool down
engine.
NOTE:
Perform the following steps before engine coolant temperature is above 90 °C (194 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
CAUTION:
Always drive vehicle at a safe speed.
6. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-224, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288284
1.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-225, "
Component Inspection (Intake Air Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace mass air flow sensor (with intake air temperature sensor).
2.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0127 IAT SENSOR-B1
(Intake air temperature too
high) Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.  Harness or connectors
(The intake air temperature sensor
circuit is open or shorted)
 Intake air temperature sensor
Revision: 2010 May2011 QX56

EC-232
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0131, P0151 A/F SENSOR 1
P0131, P0151 A/F SENSOR 1
DTC LogicINFOID:0000000006217807
DTC DETECTION LOGIC
To judge the malfunction, the diagnosis checks that t
he A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.
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 following procedure, confirm that battery voltage is 10.5 V or more at idle.
>> GO TO 2.
2.CHECK A/F SENSOR FUNCTION
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B 2)” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the indication constantly approx. 0 V?
YES >> Go to EC-233, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
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. Restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
CAUTION:
Always drive vehicle at a safe speed.
6. Maintain the following conditions fo r approximately 20 consecutive seconds.
NOTE:
 Keep the accelerator pedal as stead y as possible during cruising.
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible Cause
P0131 A/F SENSOR1 (B1)
[Air fuel ratio (A/F) sensor 1
(bank 1) circuit low voltage]
 The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 0 V.  Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
 A/F sensor 1
P0151 A/F SENSOR1 (B2)
[Air fuel ratio (A/F) sensor 1
(bank 2) circuit low voltage]
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More th
an 40 km/h (25 mph)
B/FUEL SCHDL 1.5 - 9.0 msec
Selector lever Suitable position
Revision: 2010 May2011 QX56

P0132, P0152 A/F SENSOR 1EC-235
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0132, P0152 A/F SENSOR 1
DTC LogicINFOID:0000000006217809
DTC DETECTION LOGIC
To judge the malfunction, the diagnosis checks that the
A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately high.
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 following procedure, confirm that battery voltage is 10.5 V or more at idle.
>> GO TO 2.
2.CHECK A/F SENSOR FUNCTION
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2) ” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the indication constantly approx. 5 V?
YES >> Go to EC-236, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
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. Restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine. CAUTION:
Always drive vehicle at a safe speed.
6. Maintain the following conditions for approximately 20 consecutive seconds.
NOTE:
Keep the accelerator pedal as steady as possible during cruising.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible Cause
P0132 A/F SENSOR1 (B1)
[Air fuel ratio (A/F) sensor 1
(bank 1) circuit high voltage]
 The A/F signal computed by ECM from the
A/F sensor 1 signal is constantly approx. 5 V.  Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
 A/F sensor 1
P0152 A/F SENSOR1 (B2)
[Air fuel ratio (A/F) sensor 1
(bank 2) circuit high voltage]
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 mph)
B/FUEL SCHDL 1.5 - 9.0 msec
Selector lever Suitable position
Revision: 2010 May2011 QX56

EC-264
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
NO >> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
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.
5. Maintain the following conditions for at least 10 consecutive minutes. Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-264, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217826
1.CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before three way catalyst (manifold).
Is exhaust gas leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAKAGE
1. Listen for an intake air leakage after the mass air flow sensor.
2. Check PCV hose connection.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 3.
3.CHECK A/F SENSOR 1 CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
Vehicle speed 50 - 120 km/h (31 - 75 MPH)
PBIB1216E
Revision: 2010 May2011 QX56

EC-268
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
5.PERFORM DTC CONFIRMATION PROCEDURE-III
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.
5. Maintain the following conditions for at least 10 consecutive minutes. Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-268, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217828
1.CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before three way catalyst (manifold).
Is exhaust gas leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 2.
2.CHECK FOR INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 3.
3.CHECK A/F SENSOR 1 CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
Vehicle speed 50 - 120 km/h (31 - 75 MPH)
PBIB1216E
Revision: 2010 May2011 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0420, P0430 THREE WAY CATALYST FUNCTION
DTC LogicINFOID:0000000006217851
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (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 decr
eases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of A/F sensor 1 and heated oxygen sensor
2 approaches a specified limit value, the three way catalyst (mani-
fold) malfunction is diagnosed.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
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.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 6.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
TESTING CONDITION:
Do not maintain engine speed for mo re than the specified minutes below.
1. Start engine and warm it up to the 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. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check 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).
9. Open engine hood.
10. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
11. Rev engine between 2,000 and 3,000 rpm and hold it for 3 consecutive minutes then release the acceler-
ator pedal completely.
12. Check the indication of “CATALYST”.
Which is displayed on CONSULT-III screen?
CMPLT >> GO TO 5.
INCMP >> GO TO 3.
PBIB2055E
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0420 TW CATALYST SYS-B1
[Catalyst system efficiency
below threshold (bank 1)]
 Three way catalyst (manifold) does not
operate properly.
 Three way catalyst (manifold) does not have enough oxygen storage capacity.  Three way catalyst (manifold)
 Exhaust tube
 Intake air leakage
 Fuel injector
 Fuel injector leakage
 Spark plug
 Improper ignition timing
P0430
TW CATALYST SYS-B2
[Catalyst system efficiency
below threshold (bank 2)]
Revision: 2010 May2011 QX56