2007 INFINITI QX56 service

DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-393
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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 >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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 >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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

EC-398
< SERVICE INFORMATION >
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
Diagnosis Procedure
INFOID:0000000003531900
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 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.
TER-
MI-
NAL
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

DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-399
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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.
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, F14Voltage: Approximately 5V
PBIB0138E
Continuity should exist.
Continuity should exist.

EC-400
< SERVICE INFORMATION >
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
• 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-400, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003531901
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