ignition INFINITI QX56 2004 Factory Service Manual

DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-289
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00H4W
1. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIR-
CUIT
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-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

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 CIR-
CUIT FOR OPEN AND SHORT
1. 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.
4. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)>>GO TO 4.
OK (Without CONSULT-II)>>GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0366E
Voltage: Battery voltage
PBIB2245E
Continuity should exist.

EC-292Revision: August 2007
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2004 QX56
DTC P0447 EVAP CANISTER VENT CONTROL VALVEPFP:14935
Component DescriptionUBS00H4Z
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 ModeUBS00H50
Specification data are reference values.
On Board Diagnosis LogicUBS00H51
PBIB1263E
BBIA0443E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V

Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0447
0447EVAP canister vent con-
trol valve circuit openAn 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

DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-293
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Revision: August 20072004 QX56
DTC Confirmation ProcedureUBS00H52
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, confirm battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait at least 8 seconds.
4. If 1st trip DTC is detected, go to EC-295, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF 0 58 Y

DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-295
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Revision: August 20072004 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
Yes >> GO TO 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
COLORITEM CONDITION DATA (DC Voltage)
11 7 L / YEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
PBIB1679E

EC-296Revision: August 2007
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2004 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

IPDM E/R harness connector E119

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 VALVE
EC-297
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Revision: August 20072004 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-297, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP canister vent control valve.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
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

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-299
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Revision: August 20072004 QX56
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSORPFP:22365
Component DescriptionUBS00H56
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
CONSULT-II Reference Value in Data Monitor ModeUBS00H57
Specification data are reference values.
On Board Diagnosis LogicUBS00H58
BBIA0443E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES

Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0451
0451EVAP control system pressure
sensor performanceECM detects a sloshing signal from the
EVAP control system pressure sensor

Harness or connectors

EVAP control system pressure sensor

EC-300Revision: August 2007
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
2004 QX56
DTC Confirmation ProcedureUBS00H59
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 OFF and wait at least 10 seconds.
2. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
3. Start engine and wait at least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
If 1st trip DTC is detected, go to EC-300, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H5A
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
SEF 1 94 Y
BBIA0354E

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-301
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Revision: August 20072004 QX56
2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check sensor harness connector for water.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness connector.
3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-301, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Replace EVAP control system pressure sensor.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
For wiring diagram, refer to EC-304, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionUBS00H5B
EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
Always replace O-ring with a new one.
2. Install a vacuum pump to EVAP control system pressure sensor.
3. Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.
CAUTION:

Always calibrate the vacuum pump gauge when using it.

Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or
pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
4. If NG, replace EVAP control system pressure sensor.Water should not exist.
BBIA0443E
Applied vacuum kPa
(mmHg, inHg)Voltage V
Not applied 1.8 - 4.8
-26.7 (-200, -7.87) 2.1 to 2.5V lower than above value
PBIB11 73 E

EC-302Revision: August 2007
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2004 QX56
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSORPFP:25085
Component DescriptionUBS00H5C
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
CONSULT-II Reference Value in Data Monitor ModeUBS00H5D
Specification data are reference values.
On Board Diagnosis LogicUBS00H5E
BBIA0443E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES

Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0452
0452EVAP control system pressure
sensor low inputAn excessively low voltage from the
sensor is sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted.)

EVAP control system pressure sensor