2008 INFINITI QX56 ignition

P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-237
< COMPONENT DIAGNOSIS > [VK56DE]
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DTC Confirmation ProcedureINFOID:0000000001351591
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.
TESTING CONDITION:
Before performing the following procedure, conf
irm battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Start engine and let it idle for at least 13 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-237, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351593
1.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister purge volume control
solenoid valve terminal 1 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
• Harness for open or short between EVAP canister purge volume control solenoid valve and IPDM E/R
• Harness for open or short between EVAP canister purge volume control solenoid valve and ECM
>> Repair harness or connectors.
3.CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT
FOR OPEN AND SHORT1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 45 and EVAP canister purge volume control solenoid valve terminal 2. Refer to Wiring Diagram.
BBIA0366E
Voltage: Battery voltage
PBIB2245E
Revision: March 2010 2008 QX56

P0447 EVAP CANISTER VENT CONTROL VALVEEC-239
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P0447 EVAP CANISTER VENT CONTROL VALVE
Component DescriptionINFOID:0000000001351596
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the
canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
On Board Diagnosis LogicINFOID:0000000001351598
DTC Confirmation ProcedureINFOID:0000000001351599
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.
TESTING CONDITION:
Before performing the following procedure, conf irm battery voltage is more than 11V at idle.
WITH CONSULT-III
1. Start engine and wait at least 8 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-239, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351601
1.INSPECTION START
Do you have CONSULT-III?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
PBIB1263E
BBIA0443E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0447
0447 EVAP canister vent con-
trol valve circuit open An improper voltage signal is sent to ECM
through EVAP canister vent control valve. • Harness or connectors
(The valve circuit is open or shorted.)
• EVAP canister vent control valve
Revision: March 2010 2008 QX56

EC-240
< COMPONENT DIAGNOSIS >[VK56DE]
P0447 EVAP CANISTER VENT CONTROL VALVE
2.CHECK EVAP CANISTER VE
NT CONTROL VALVE CIRCUIT
With CONSULT-III
1. Turn ignition switch OFF and then turn ON.
2. Select “VENT CONTROL/V” in “ACTIVE TEST” mode with CONSULT-III.
3. Touch “ON/OFF” on CONSULT-III screen.
4. Check for operating sound of the valve. Clicking noise should be heard.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK EVAP CANISTER VENT CONT ROL VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister vent control valve harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister vent control valve termi- nal 2 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E41, C1
• Harness for open or short between EVAP canister vent control valve and IPDM E/R
>> Repair harness or connectors.
5.CHECK EVAP CANISTER VENT CONTROL VALVE OU TPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 117 and EVAP canister vent control valve terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Voltage: Battery voltage
BBIA0443E
PBIB0192E
Continuity should exist.
Revision: March 2010 2008 QX56

P0447 EVAP CANISTER VENT CONTROL VALVEEC-241
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Check the following.
• Harness connectors E41, C1
• Harness for open or short between EVAP c
anister vent control valve and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EV AP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 8.
NG >> Clean the rubber tube using an air blower.
8.CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-241, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP canister vent control valve.
9.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351602
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-III
1. Remove EVAP canister vent c ontrol valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
3. Reconnect harness connectors disconnected.
4. Turn ignition switch ON.
5. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
6. Check air passage continuity and operation delay time. Make sure new O-ring is installed properly.
Operation takes less than 1 second.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
7. Clean the air passage (portion A to B) of EVAP canister vent control valve using an air blower.
8. Perform step 6 again.
Without CONSULT-III
PBIB1033E
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
Revision: March 2010 2008 QX56

P0448 EVAP CANISTER VENT CONTROL VALVEEC-243
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P0448 EVAP CANISTER VENT CONTROL VALVE
Component DescriptionINFOID:0000000001351603
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the
canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
On Board Diagnosis LogicINFOID:0000000001351605
DTC Confirmation ProcedureINFOID:0000000001351606
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-III
1. Turn ignition switch ON and wait at least 5 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and let it idle for at least 1 minute.
5. Repeat next procedures 3 times.
a. Increase the engine speed up to 3,000 to 3,500 rpm and keep it for 2 minutes and 50 seconds to 3 min- utes.
Never exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for about 5 seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-244, "
Diagnosis Procedure".
If 1st trip DTC is not detected, go to the next step.
8. Repeat next procedure 20 times.
PBIB1263E
BBIA0443E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0448
0448 EVAP canister vent con-
trol valve close EVAP canister vent control valve remains
closed under specified driving conditions. • EVAP canister vent control valve
• EVAP control system pressure sensor
and the circuit
• Blocked rubber tube to EVAP canister
vent control valve
• EVAP canister is saturated with water
Revision: March 2010 2008 QX56

EC-244
< COMPONENT DIAGNOSIS >[VK56DE]
P0448 EVAP CANISTER VENT CONTROL VALVE
a. Quickly increase the engine speed up to 4,000 to 4,500 rpm or more and keep it for 25 to 30 seconds.
b. Fully released accelerator pedal and keep engine idle for at least 35 seconds.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to
EC-244, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351608
1.CHECK RUBBER TUBE
1. Turn ignition switch OFF.
2. Disconnect rubber tube connected to EV AP canister vent control valve.
3. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 2.
NG >> Clean rubber tube using an air blower.
2.CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-245, "
Component Inspection".
OK or NG
OK >> GO TO 3.
NG >> Replace EVAP canister vent control valve.
3.CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor attached.
2. Check if water will drain from the EVAP canister.
Ye s o r N o
Ye s > > G O T O 4 .
No >> GO TO 6.
PBIB0972E
BBIA0443E
BBIA0351E
Revision: March 2010 2008 QX56

P0448 EVAP CANISTER VENT CONTROL VALVEEC-245
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4.CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• EVAP canister for damage
• EVAP hose between EVAP canister and vehi cle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
6.CHECK EVAP CONTRO L SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 7.
NG >> Replace EVAP control system pressure sensor.
7.CHECK EVAP CONTROL SYS TEM PRESSURE SENSOR
Refer to EC-248, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351609
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-III
1. Remove EVAP canister vent c ontrol valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
3. Reconnect harness connectors disconnected.
4. Turn ignition switch ON.
5. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
6. Check air passage continuity and operation delay time. Make sure that new O-ring is installed properly.Water should not exist.
PBIB1033E
Revision: March 2010
2008 QX56

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOREC-247
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P0451 EVAP CONTROL SYST
EM PRESSURE SENSOR
Component DescriptionINFOID:0000000001351610
The EVAP control system pressure sens or detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
On Board Diagnosis LogicINFOID:0000000001351612
NOTE:
If DTC P0451 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-293
.
DTC Confirmation ProcedureINFOID:0000000001351613
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-III
1. Start engine and wait at least 40 seconds. NOTE:
Do not depress accelerator pedal even slightly.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-247, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351614
1.CHECK GROUND CONNECTIONS
BBIA0443E
PBIB1207E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0451
0451 EVAP control system pressure
sensor performance ECM detects a sloshing signal from the
EVAP control system pressure sensor • Harness or connectors
• EVAP control system pressure sensor
Revision: March 2010
2008 QX56