2007 INFINITI QX56 service

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-177
< SERVICE INFORMATION >
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1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
CAUTION:
• Discard any heated oxygen sensor which has been dropped
from a height of more than 0.5 m (19.7 in) onto a hard surface
such as a concrete floor; use a new one.
• Before installing new oxygen sensor, clean exhaust system
threads using Oxygen Sensor Thread Cleaner tool J-43897-18
or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationINFOID:0000000003531671
HEATED OXYGEN SENSOR 2
Refer to EM-21.
Terminal No. Resistance
2 and 3 8 - 10 Ω at 25°C (77°F)
1 and 2, 3, 4
∞ Ω
(Continuity should not exist)
4 and 1, 2, 3
SEF249Y

EC-178
< SERVICE INFORMATION >
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
Component DescriptionINFOID:0000000003531672
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing 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.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531673
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531674
DTC Confirmation ProcedureINFOID:0000000003531675
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If 1st trip DTC is detected, go to EC-182, "
Diagnosis Procedure".
WITH GST
Following the procedure “WITH CONSULT-II” above.
PBIB1842E
MONITOR ITEM CONDITION SPECIFICATION
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 DTC detecting condition Possible cause
P0075
0075
(Bank 1)
Intake valve timing control
solenoid valve circuitAn improper voltage is sent to the ECM
through intake valve timing control solenoid
valve.• Harness or connectors
(Intake valve timing control solenoid valve
circuit is open or shorted.)
• Intake valve timing control solenoid valve P0081
0081
(Bank 2)
SEF058Y

DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
EC-179
< SERVICE INFORMATION >
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Wiring DiagramINFOID:0000000003531676
BANK 1
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
BBWA2860E

EC-180
< SERVICE INFORMATION >
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
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
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

DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
EC-181
< SERVICE INFORMATION >
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BANK 2
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.
BBWA2861E

EC-182
< SERVICE INFORMATION >
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003531677
1.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect intake valve timing control solenoid valve harness connector.
3. Turn ignition switch ON.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
11 L GIntake valve timing control
solenoid valve (Bank 2)[Engine is running]
•Warm-up condition
• Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
•Warm-up condition
• Engine speed: 2,000rpm7 - 12V
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
1. Intake valve timing control position
sensor (bank 2)2. Intake valve timing control solenoid
valve (bank 2)3. Drive belt
4. Radiator hose 5. Intake valve timing control solenoid
valve (bank 1)6. Intake valve timing control position
sensor (bank 1)
BBIA0771E

DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
EC-183
< SERVICE INFORMATION >
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4. Check voltage between intake valve timing control solenoid
valve terminal 2 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• IPDM E/R harness connector E119
• Harness for open or short between intake valve timing control solenoid valve and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN
AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following;
ECM terminal 10 and intake valve timing control solenoid valve (Bank 1) terminal 1 or
ECM terminal 11 and intake valve timing control solenoid valve (Bank 2) terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE
Refer to EC-183, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EC-184
.
5.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003531678
INTAKE VALVE TIMING CONTROL SOLENOID VALVE
1. Disconnect intake valve timing control solenoid valve harness connector.Voltage: Battery voltage
PBIB0192E
Continuity should exist.

EC-184
< SERVICE INFORMATION >
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
2. Check resistance between intake valve timing control solenoid
valve terminals as follows.
If NG, replace intake valve timing control solenoid valve. Refer to
EC-184
.
If OK, go to next step.
3. Remove intake valve timing control solenoid valve. Refer to EC-
184.
4. Provide 12V DC between intake valve timing control solenoid
valve terminals and then interrupt it. Make sure that the plunger
moves as shown in the figure.
CAUTION:
Do not apply 12V DC continuously for 5 seconds or more.
Doing so may result in damage to the coil in intake valve
timing control solenoid valve.
If NG, replace intake valve timing control solenoid valve. Refer to
EC-184
.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.
Removal and InstallationINFOID:0000000003531679
INTAKE VALVE TIMING CONTROL SOLENOID VALVE (BANK 2)
Removal
1. Remove engine room cover using power tool. Refer to EM-12, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-15, "
Removal and Installation".
3. Remove drive belt. Refer to EM-13, "
Removal and Installation".
4. Disconnect intake valve timing control solenoid valve (bank 2) connector.
5. Remove intake valve timing control solenoid valve (bank 2) (2)
from intake valve control solenoid cover (bank 2) (1).
Installation
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (3) of the intake valve timing control solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
INTAKE VALVE TIMING CONTROL SOLENOID VALVE (BANK 1)
Removal
1. Remove drive belt. Refer to EM-13, "Removal and Installation".
Terminals Resistance
1 and 2 7.0 - 7.5Ω [at 20°C (68°F)]
1 or 2 and ground∞Ω
(Continuity should not exist)
PBIB0193E
PBIB2275E
LBIA0477E
Intake valve timing control solenoid valve bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)