INFINITI QX56 2007 Factory Service Manual

EC-388
< SERVICE INFORMATION >
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
Wiring Diagram
INFOID:0000000003531886
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.
BBWA2095E

DTC P0448 EVAP CANISTER VENT CONTROL VALVE
EC-389
< SERVICE INFORMATION >
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Diagnosis ProcedureINFOID:0000000003531887
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-390, "
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
Yes >> GO TO 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.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 7 L / YEVAP canister vent control
valve[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
BBIA0443E
BBIA0351E

EC-390
< SERVICE INFORMATION >
DTC P0448 EVAP CANISTER VENT CONTROL VALVE
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-394, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003531888
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.Water should not exist.
PBIB1033E

DTC P0448 EVAP CANISTER VENT CONTROL VALVE
EC-391
< SERVICE INFORMATION >
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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.
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-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 that 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.
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
PBIB1679E
PBIB1033E
Condition Air passage continuity between A and B
12V direct current supply between
terminals 1 and 2No
OFF Yes
PBIB1034E

EC-392
< SERVICE INFORMATION >
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000003531889
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 ModeINFOID:0000000003531890
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531891
NOTE:
If DTC P0451 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-447
.
DTC Confirmation ProcedureINFOID:0000000003531892
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.
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

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-393
< SERVICE INFORMATION >
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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-393, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531893
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
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-394, "
Component Inspection".
OK or NG
OK >> GO TO 4.
SEF194Y
BBIA0354E
Water should not exist.
BBIA0443E

EC-394
< SERVICE INFORMATION >
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
NG >> Replace EVAP control system pressure sensor.
4.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
For wiring diagram, refer to EC-397, "
Wiring Diagram".
>>INSPECTION END
Component InspectionINFOID:0000000003531894
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.
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
PBIB1173E

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-395
< SERVICE INFORMATION >
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DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000003531895
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 ModeINFOID:0000000003531896
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531897
NOTE:
If DTC P0452 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-447
.
DTC Confirmation ProcedureINFOID:0000000003531898
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:
Always perform test at a temperature of 5°C (41°F) or more.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
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 sen-
sor is sent to ECM.• Harness or connectors
(The sensor circuit is open or shorted.)
• EVAP control system pressure sensor

EC-396
< SERVICE INFORMATION >
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
4. Select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that “FUEL T/TMP SE” is more than 0°C (32°F).
6. Start engine and wait at least 20 seconds.
If 1st trip DTC is detected, go to EC-398, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 107 (Fuel tank tem-
perature sensor signal) and ground is less than 4.2V.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and wait at least 20 seconds.
5. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-398, "
Diagnosis Procedure".
SEF194Y
PBIB1110E

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-397
< SERVICE INFORMATION >
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Wiring DiagramINFOID:0000000003531899
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.
BBWA2096E