INFINITI QX56 2008 Factory Service Manual

EC-102
< COMPONENT DIAGNOSIS >[VK56DE]
P0037, P0038, P0057,
P0058 HO2S2 HEATER
4.CHECK HO2S2 HEATER OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-102, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351391
HEATED OXYGEN SENSOR 2 HEATER
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.
DTC Te r m i n a l s
Bank
ECM Sensor
P0037, P0038 6 21
P0057, P0058 25 22
Continuity should exist.
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
Revision: March 2010 2008 QX56

P0075, P0081 IVT CONTROL SOLENOID VALVEEC-103
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0075, P0081 IVT CONTROL SOLENOID VALVE
Component DescriptionINFOID:0000000001351393
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.
On Board Diagnosis LogicINFOID:0000000001351395
DTC Confirmation ProcedureINFOID:0000000001351396
NOTE:
If DTC Confirmation Procedure has been previously conducted, alw
ays turn ignition switch OFF and
wait at least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Start engine and let it idle for 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-103, "
Diagnosis Procedure".
WITH GST
Following the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351398
1.CHECK INTAKE VALVE TIMING CONTROL SO LENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect intake valve timing control solenoid valve harness connector.
PBIB1842E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0075
0075
(Bank 1) Intake valve timing control
solenoid valve circuit An 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)
BBIA0771E
Revision: March 2010
2008 QX56

EC-104
< COMPONENT DIAGNOSIS >[VK56DE]
P0075, P0081 IVT CONTROL SOLENOID VALVE
3. Turn ignition switch ON.
4. Check voltage between intake valve timing control solenoid
valve terminal 2 and ground with CONSULT-III 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-104, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning intake valve timing control solenoid valve. Refer to EC-500
.
5.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351399
INTAKE VALVE TIMING CONTROL SOLENOID VALVE
1. Disconnect intake valve timing control solenoid valve harness connector.
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)
Voltage: Battery voltage
PBIB0351E
Continuity should exist.
Revision: March 2010 2008 QX56

P0075, P0081 IVT CONTROL SOLENOID VALVEEC-105
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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-500
.
If OK, go to next step.
3. Remove intake valve timing control solenoid valve. Refer to EC-
500.
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-500
.
NOTE:
Always replace O-ring when intake valve timing control
solenoid valve is removed.
Terminals Resistance
1 and 2 7.1 - 7.7Ω [at 20°C (68 °F)]
1 or 2 and ground ∞Ω
(Continuity should not exist)
MBIB0027E
PBIB2388E
Revision: March 2010 2008 QX56

EC-106
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
P0101 MAF SENSOR
Component DescriptionINFOID:0000000001351401
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor c
ontrols the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to the hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
On Board Diagn osis LogicINFOID:0000000001351403
DTC Confirmation ProcedureINFOID:0000000001351404
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
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.
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at leas t 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Run engine for at least 10 seconds at idle speed.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-109, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
PROCEDURE FOR MALFUNCTION B
NOTE:
Check vehicle specifications and VIN, then select the procedure to be performed. (Refer to the table below.)
BBIA0355E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0101
0101 Mass air flow sensor circuit
range/performance A)
A high voltage from the sensor is sent to ECM
under light load driving condition. • Harness or connectors
(The sensor circuit is open or
shorted.)
• Mass air flow sensor
• EVAP control system pressure sensor
• Intake air temperature sensor
B) A low voltage from the sensor is sent to ECM
under heavy load driving condition. • Harness or connectors
(The sensor circuit is open or
shorted.)
• Intake air leaks
• Mass air flow sensor
• EVAP control system pressure sensor
• Intake air temperature sensor
Revision: March 2010 2008 QX56

P0101 MAF SENSOREC-107
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Procedure for Malfunction B-a
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature. If engine cannot be started, go to EC-109, "
Diagnosis Procedure".
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
4. Increases engine speed to about 4,000 rpm.
5. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-109, "
Diagnosis Procedure".
If OK, go to following step.
6. Maintain the following conditions for at least 10 consecutive seconds. CAUTION:
Always drive vehicle at a safe speed.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-109, "
Diagnosis Procedure".
Procedure for Malfunction B-b
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
Vehicle specification Vehicle serial number Procedure
2WD with ASCD Up to 912536
B-a
From 912537 B-b
2WD with ICC Up to 914347
B-a
From 914348 B-b
4WD with ASCD Up to 913067
B-a
From 913068 B-b
4WD with ICC Up to 912422
B-a
From 912423 B-b
PBIB3457E
ENG SPEEDMore than 2,000 rpm
TP SEN 1-B1 More than 3 V
TP SEN 2-B1 More than 3 V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
Revision: March 2010
2008 QX56

EC-108
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
If engine cannot be started, go to
EC-109, "Diagnosis Procedure".
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
4. Increases engine speed to about 4,000 rpm.
5. Monitor the linear voltage rise in response to engine speed increases.
If NG, go to EC-109, "
Diagnosis Procedure".
If OK, go to following step.
6. Maintain the following conditions for at least 10 consecutive seconds. CAUTION:
Always drive vehicle at a safe speed.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-109, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000001351405
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-109, "
Diagnosis Procedure".
PBIB3457E
ENG SPEED More than 2,000 rpm
TP SEN 1-B1 More than 1.5 V
TP SEN 2-B1 More than 1.5 V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
SEF534P
Revision: March 2010
2008 QX56

P0101 MAF SENSOREC-109
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Diagnosis ProcedureINFOID:0000000001351407
1.INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A >> GO TO 3.
B >> GO TO 2.
2.CHECK INTAKE SYSTEM
Check the following for connection.
• Air duct
• Vacuum hoses
• Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
3.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 4.
NG >> Repair or replace ground connections.
4.CHECK MAF SENSOR PO WER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor harness connector.
2. Turn ignition switch ON.
BBIA0354E
BBIA0368E
Revision: March 2010 2008 QX56

EC-110
< COMPONENT DIAGNOSIS >[VK56DE]
P0101 MAF SENSOR
3. Check voltage between MAF sensor terminal 2 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between IPDM E/R and mass air flow sensor
• Harness for open or short between mass air flow sensor and ECM
>> Repair harness or connectors.
6.CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67. Refer to Wiring Diagram.
4. 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 MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51. Refer to Wiring Diagram.
2. 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 INTAKE AIR TEMPERATURE SENSOR
Refer to EC-120, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9.CHECK EVAP CONTROL SY STEM PRESSURE SENSOR
Refer to EC-248, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK MASS AIR FLOW SENSOR
Refer to E C - 111 , "
Component Inspection".
OK or NG
Voltage: Battery voltage
PBIB1168E
Continuity should exist.
Continuity should exist.
Revision: March 2010 2008 QX56

P0101 MAF SENSOREC-111
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351408
MASS AIR FLOW SENSOR
With CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check i ndication under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following. • Crushed air ducts
• Malfunctioning seal of air cleaner element
• Uneven dirt of air cleaner element
• Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again. If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor har ness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.7 - 2.1
Idle to about 4,000 rpm 1.0 - 1.3 to Approx. 2.4*
ConditionMAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.7 - 2.1
Idle to about 4,000 rpm 1.0 - 1.3 to Approx. 2.4*
PBIB1106E
Revision: March 2010 2008 QX56