2007 INFINITI QX56 engine

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-133
< SERVICE INFORMATION >
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6.CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-80, "
Fuel Pressure Check" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-80, "
Fuel Pressure Check" .
GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7.DETECT MALFUNCTIONING PART
1. Check the following.
- Clogged and bent fuel hose and fuel tube
- Clogged fuel filter
- Fuel pump and its circuit (Refer to EC-613
.)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-80, "
Fuel Pressure Check" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-626
.)
- Fuel injector and its circuit (Refer to EC-608
.)
- Intake air leakage
- Low compression pressure (Refer to EM-64, "
On-Vehicle Service".)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11 .CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 12.
PBIB0133E

EC-134
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
12.CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
• For DTC P0130, P0150, refer to EC-225, "
DTC Confirmation Procedure" .
• For DTC P0131, P0151, refer to EC-234, "
DTC Confirmation Procedure" .
• For DTC P0132, P0132, refer to EC-242, "
DTC Confirmation Procedure" .
• For DTC P0133, P0153, refer to EC-250, "
DTC Confirmation Procedure" .
• For DTC P2A00, P2A03, refer to EC-588, "
DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13.CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> GO TO 15.
15.DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG >> Detect malfunctioning part according to EC-90, "
Symptom Matrix Chart" .
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of power steering, alternator, A/C compressor, etc. is excessive
- Noise from engine
PBIB2332E

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-135
< SERVICE INFORMATION >
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- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
• Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >>INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-194 .
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and
then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-117, "
ECM Re-communicating Function".
PBIB2370E

EC-140
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis Procedure
INFOID:0000000003531637
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• 10A fuse
• Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
• Idle speedBody ground
109 L/W Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
B/WECM ground[Engine is running]
• Idle speedBody ground
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

DTC P0011, P0021 IVT CONTROL
EC-149
< SERVICE INFORMATION >
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DTC P0011, P0021 IVT CONTROL
DescriptionINFOID:0000000003531648
SYSTEM DESCRIPTION
*: This signal is sent to the ECM through CAN communication line
This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing (IVT) control sole-
noid valve depending on driving status. This makes it possible to control the shut/open timing of the intake
valve to increase engine torque in low/mid speed range and output in high-speed range.
COMPONENT DESCRIPTION
Intake Valve Timing Control Solenoid Valve
Intake Valve Timing (IVT) control solenoid valve is activated by ON/
OFF pulse duty (ratio) signals from the ECM.
The IVT control solenoid valve changes the oil amount and direction
of flow through intake valve timing control unit or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
Intake Valve Timing Control Position Sensor
Sensor Input signal to ECM function ECM Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Intake valve
timing controlIntake valve timing control
solenoid valve Intake valve timing control position sensor Intake valve timing signal
Engine coolant temperature sensor Engine coolant temperature
Wheel sensor Vehicle speed*
PBIB3276E
PBIB1842E

EC-150
< SERVICE INFORMATION >
DTC P0011, P0021 IVT CONTROL
Intake valve timing control position sensors are located in the front of
cylinder heads in both bank 1 and bank 2.
This sensor uses a Hall IC.
The cam position is determined by the intake camshaft sprocket con-
cave (in three places). The ECM provides feedback to the intake
valve timing control for appropriate target valve open-close timing
according to drive conditions based on detected cam position.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531649
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531650
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation ProcedureINFOID:0000000003531651
CAUTION:
Always drive at a safe speed.
NOTE:
•If DTC P0011 or P0021 is displayed with DTC P0075, P0081, P1140 or P1145, first perform the trouble
diagnosis for EC-178
or EC-457.
SEF359Z
MONITOR ITEM CONDITION SPECIFICATION
INT/V TIM (B1)
INT/V TIM (B2)• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadIdle−5° - 5°CA
2,000 rpm Approx. 0° - 20°CA
INT/V SOL (B1)
INT/V SOL (B2)• Engine: After warming up
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadIdle 0% - 2%
2,000 rpm Approx. 25% - 50%
DTC No. Trouble diagnosis name Detecting condition Possible cause
P0011
0011
(Bank 1)
Intake valve timing control
performanceAThe alignment of the intake valve timing
control has been misresistered.• Harness or connectors
(Intake valve timing control solenoid
valve circuit is open or shorted.)
• Harness or connectors
(Intake valve timing control position
sensor circuit is open or shorted.)
• Intake valve timing control solenoid
valve
• Intake valve timing control position
sensor
• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Accumulation of debris to the signal
pick-up portion of the camshaft
sprocket
• Timing chain installation
• Foreign matter caught in the oil
groove for intake valve timing control P0021
0021
(Bank 2)BThere is a gap between angle of target and
phase-control angle degree.
Detected items Engine operating condition in fail-safe mode
Intake valve timing control The signal is not energized to the solenoid valve and the valve control does not function

DTC P0011, P0021 IVT CONTROL
EC-151
< SERVICE INFORMATION >
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• 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 between 10V and 16V at
idle.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Maintain the following conditions for at least 10 consecutive sec-
onds.
4. Maintain the following conditions for at least 20 consecutive seconds.
5. If 1st trip DTC is detected, go to EC-155, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Maintain the following conditions for at least 10 consecutive sec-
onds.
4. If 1st trip DTC is detected, go to EC-155, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
ENG SPEED More than 2,000 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70°C (158°F)
Selector lever 1st or 2nd position
Driving location uphillDriving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
ENG SPEED Idle
COOLAN TEMP/S More than 70°C (158°F)
Selector lever P or N position
PBIB0164E
ENG SPEED 1,700 - 3,175 rpm (A constant rotation is maintained.)
COOLAN TEMP/S More than 70°C (158°F)
Selector lever 1st or 2nd position
Driving location uphillDriving vehicle uphill
(Increased engine load will help maintain the driving con-
ditions required for this test.)
PBIB0164E

DTC P0011, P0021 IVT CONTROL
EC-153
< SERVICE INFORMATION >
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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.)TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
10 WIntake valve timing control
solenoid valve (Bank 1)[Engine is running]
•Warm-up condition
• Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
•Warm-up condition
• Engine speed: 2,000rpm7 - 12V
72 YIntake valve timing control
position sensor (Bank 1)[Engine is running]
•Warm-up condition
• Idle speed0 - 1.0V
[Engine is running]
• Engine speed: 2,000rpm0 - 1.0V
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
PBIB1790E
PBIB2046E