2004 INFINITI QX56 Air

EC-298Revision: August 2007
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2004 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 2No
OFF Yes
PBIB1034E

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

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-305
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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 ProcedureUBS00H5H
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.
2. CHECK CONNECTOR
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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
32 LEVAP control system pressure
sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
48 SBSensor power supply
(EVAP control system pressure
sensor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground [Engine is running]

Warm-up condition

Idle speedApproximately 0V
BBIA0354E
Water should not exist.
BBIA0443E

EC-306Revision: August 2007
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2004 QX56
3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between EVAP control system pressure sensor
terminal 3 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 C1, E41

Harness connectors E5, F14

Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between EVAP control system pressure sensor terminal 1 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 >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness connectors E5, F14

Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors. Voltage: Approximately 5V
PBIB0138E
Continuity should exist.

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-307
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Revision: August 20072004 QX56
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Check harness continuity between ECM terminal 32 and EVAP control system pressure sensor terminal
2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness connectors E5, F14

Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-307, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H5I
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.Continuity should exist.
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

DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-311
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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 ProcedureUBS00H5O
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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
32 LEVAP control system pressure
sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
48 SBSensor power supply
(EVAP control system pressure
sensor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
BBIA0354E

EC-312Revision: August 2007
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
2004 QX56
2. CHECK CONNECTOR
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 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between EVAP control system pressure sensor
terminal 3 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 C1, E41

Harness connectors E5, F14

Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors. Water should not exist.
BBIA0443E
Voltage: Approximately 5V
PBIB0138E