2008 INFINITI QX56 ignition

EC-248
< COMPONENT DIAGNOSIS >[VK56DE]
P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK EVAP CONTROL SYSTEM PRESS URE 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 SY STEM PRESSURE SENSOR
Refer to EC-248, "
Component Inspection".
OK or NG
OK >> GO TO 4.
NG >> Replace EVAP control system pressure sensor.
4.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
For wiring diagram, refer to EC-251, "
Diagnosis Procedure".
>> INSPECTION END
Component InspectionINFOID:0000000001351615
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.
BBIA0354E
Water should not exist.
BBIA0443E
Revision: March 2010 2008 QX56

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOREC-249
< COMPONENT DIAGNOSIS > [VK56DE]
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3. Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.
CAUTION:
• Always calibrate the vacuum pu mp gauge when using it.
• Do not apply below -93.3 kP a (-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
Revision: March 2010 2008 QX56

EC-250
< COMPONENT DIAGNOSIS >[VK56DE]
P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000001351616
The EVAP control system pressure sens
or detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
On Board Diagn osis LogicINFOID:0000000001351618
NOTE:
If DTC P0452 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-293
.
DTC Confirmation ProcedureINFOID:0000000001351619
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-III
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.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Make sure that “FUEL T/TMP SE” is more than 0 °C (32° F).
6. Start engine and wait at least 20 seconds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-251, "
Diagnosis Procedure".
BBIA0443E
PBIB1207E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0452
0452 EVAP control system pressure
sensor low input An 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
Revision: March 2010 2008 QX56

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOREC-251
< COMPONENT DIAGNOSIS > [VK56DE]
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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-251, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001351621
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
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 SYS TEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
PBIB1110E
BBIA0354E
Water should not exist.
BBIA0443E
Revision: March 2010 2008 QX56

EC-252
< COMPONENT DIAGNOSIS >[VK56DE]
P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2. Check voltage between EVAP control system pressure sensor
terminal 3 and ground with CONSULT-III 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 sy stem 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, F14 Voltage: Approximately 5V
PBIB0138E
Continuity should exist.
Continuity should exist.
Revision: March 2010
2008 QX56

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOREC-253
< COMPONENT DIAGNOSIS > [VK56DE]
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• Harness for open or short between EVAP c
ontrol system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK EVAP CONTROL SYS TEM PRESSURE SENSOR
Refer to EC-253, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001351622
EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pr essure 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 pu mp gauge when using it.
• Do not apply below -93.3 kP a (-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
Revision: March 2010 2008 QX56

EC-254
< COMPONENT DIAGNOSIS >[VK56DE]
P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
Component DescriptionINFOID:0000000001351623
The EVAP control system pressure sens
or detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
On Board Diagn osis LogicINFOID:0000000001351625
NOTE:
If DTC P0453 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-293
.
DTC Confirmation ProcedureINFOID:0000000001351626
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-III
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.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Make sure that “FUEL T/TMP SE” is more than 0 °C (32° F).
BBIA0443E
PBIB1207E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0453
0453 EVAP control system pressure
sensor high input An excessively high voltage from the
sensor is sent to ECM. • Harness or connectors
(The sensor circuit is open or shorted.)
• EVAP control system pressure sensor
• EVAP canister vent control valve
• EVAP canister
• Rubber hose from EVAP canister vent
control valve to vehicle frame
Revision: March 2010 2008 QX56

P0453 EVAP CONTROL SYSTEM PRESSURE SENSOREC-255
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
6. Start engine and wait at least 20 seconds.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to
EC-255, "
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-255, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001351628
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
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 SYS TEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
PBIB1110E
BBIA0354E
Water should not exist.
BBIA0443E
Revision: March 2010 2008 QX56