INFINITI QX56 2006 Factory Service Manual

EC-390Revision: November 2009
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2006 QX56
Wiring DiagramUBS00H53
BBWA2095E

DTC P0447 EVAP CANISTER VENT CONTROL VALVEEC-391
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EC
Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
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.
Diagnostic ProcedureUBS00H54
1. INSPECTION START
Do you have CONSULT-II?
Ye s o r N o
Ye s > > G O T O 2 .
No >> GO TO 3.
2. CHECK EVAP CANISTER VENT CONTROL VALVE CIRCUIT
With CONSULT-II
1. Turn ignition switch OFF and then turn ON.
2. Select “VENT CONTROL/V ” in “ACTIVE TEST ” mode with CONSULT-II.
3. Touch “ON/OFF” on CONSULT-II 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.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 7 L / Y EVAP canister vent control
valve
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
PBIB1679E

EC-392Revision: November 2009
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2006 QX56
3. CHECK EVAP CANISTER VENT CONTROL 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 1 and ground with CONSULT-II 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 OUTPUT 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 2.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. Voltage: Battery voltage
BBIA0443E
PBIB0152E
Continuity should exist.

DTC P0447 EVAP CANISTER VENT CONTROL VALVEEC-393
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Revision: November 2009 2006 QX56
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E41, C1

Harness for open or short between EVAP canister 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 EVAP 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-393, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP canister vent control valve.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionUBS00H55
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-II
1. Remove EVAP canister vent control 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.
PBIB1033E
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
PBIB1679E

EC-394Revision: November 2009
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2006 QX56
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-II
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
3. Check air passage continuity and operation delay time under the following conditions.
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.
4. Clean the air passage (portion A to B ) of EVAP canister vent control valve using an air blower.
5. Perform step 3 again.
PBIB1033E
Condition Air passage continuity between A and B
12V direct current supply between
terminals 1 and 2 No
OFF Yes
PBIB1034E

DTC P0448 EVAP CANISTER VENT CONTROL VALVEEC-395
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Revision: November 2009 2006 QX56
DTC P0448 EVAP CANISTER VENT CONTROL VALVEPFP:16935
Component DescriptionUBS00HB1
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.
CONSULT-II Reference Value in Data Monitor ModeUBS00HB2
Specification data are reference values.
On Board Diagnosis LogicUBS00HB3
PBIB1263E
BBIA0443E
MONITOR ITEMCONDITION SPECIFICATION
VENT CONT/V

Ignition switch: ON OFF
DTC No. Trouble diagnosis nameDTC 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

EC-396Revision: November 2009
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
2006 QX56
DTC Confirmation ProcedureUBS00HB4
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 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-II.
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 minutes.
Never exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for about 5 seconds.
6. If 1st trip DTC is detected, go to EC-398, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the next step.
7. Repeat next procedure 20 times.
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.
8. If 1st trip DTC is detected, go to EC-398, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
PBIB0972E

DTC P0448 EVAP CANISTER VENT CONTROL VALVEEC-397
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Revision: November 2009 2006 QX56
Wiring DiagramUBS00HB5
BBWA2095E

EC-398Revision: November 2009
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
2006 QX56
Specification data are reference values and are measured between each terminal and ground.
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.
Diagnostic ProcedureUBS00HB6
1. CHECK RUBBER TUBE
1. Turn ignition switch OFF.
2. Disconnect rubber tube connected to EVAP 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-400, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace EVAP canister vent control valve.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 7 L / Y EVAP canister vent control
valve
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
BBIA0443E

DTC P0448 EVAP CANISTER VENT CONTROL VALVEEC-399
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Revision: November 2009 2006 QX56
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.
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 vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
6. CHECK EVAP CONTROL 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 SYSTEM PRESSURE SENSOR
Refer to EC-404, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
BBIA0351E
Water should not exist.