2011 INFINITI QX56 air condition

EC-314
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0441 EVAP CONTROL SYSTEM
5. Set voltmeter probes to ECM harness connector terminals under the following conditions.
6. Check EVAP control system pressure sensor value at idle speed and note it.
7. Establish and maintain the following conditions for at least 1 minute.
8. Verify that EVAP control system pressure sensor
value stays 0.1 V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-314, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006288306
1.CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
Is the inspection result normal?
YES-1 >> With CONSULT-III: GO TO 2.
YES-2 >> Without CONSULT-III: GO TO 3.
NO >> Replace EVAP canister. Refer to FL-12, "
Removal and Installation".
2.CHECK PURGE FLOW
WITH CONSULT-III
1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port.
2. Start engine and let it idle.
3. Select “PURG VOL CONT/V” in “A CTIVE TEST” mode with CONSULT-III.
4. Touch “Qd” and “Qu” on CONSULT-III screen to adjust “PURG VOL CONT/V” opening and check vacuum
existence.
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 4.
3.CHECK PURGE FLOW
WITHOUT CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-45, "
EVAPORATIVE
EMISSION SYSTEM : System Description".
ECM
Connector +–
Te r m i n a l Te r m i n a l
E80 143
(EVAP control system pressure sensor signal) 150
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PURG VOL CONT/V Vacuum 100% Existed0% Not existed
Revision: 2010 May2011 QX56

P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-321
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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6. Touch “Qd” and “Qu” on CONSULT-III screen to adjust “PURG
VOL C/V” opening and check air passage continuity of EVAP
canister purge volume control solenoid valve under the following
conditions.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
3. Disconnect EVAP purge hoses connected to EVAP c anister purge volume control solenoid valve.
4. Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace EVAP canister purge volume control solenoid valve. Refer to FL-10, "
Hydraulic Layout".
Condition
(PURG VOL C/V value) Air passage continuity
between (A) and (B)
100% Existed 0% Not existed
JMBIA0068ZZ
Condition Air passage continuity
between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Existed
No supply Not existed
JMBIA0068ZZ
Revision: 2010 May2011 QX56

EC-324
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0444, P0445 EVAP CANISTER P
URGE VOLUME CONTROL SOLENOID
VALVE
6. Touch “Qd” and “Qu” on CONSULT-III screen to adjust “PURG
VOL C/V” opening and check air passage continuity of EVAP
canister purge volume control solenoid valve under the following
conditions.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve harness connector.
3. Disconnect EVAP purge hoses connected to EVAP canister purge volume control solenoid valve.
4. Check air passage continuity of EVAP canister purge volume control solenoid valve under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace EVAP canister purge volume control solenoid valve. Refer to FL-10, "
Hydraulic Layout".
Condition
(PURG VOL C/V value) Air passage continuity
between (A) and (B)
100% Existed 0% Not existed
JMBIA0068ZZ
Condition Air passage continuity
between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Existed
No supply Not existed
JMBIA0068ZZ
Revision: 2010 May2011 QX56

P0447 EVAP CANISTER VENT CONTROL VALVEEC-327
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Component Inspection (EVAP C
anister Vent Control Valve)INFOID:0000000006288312
1.CHECK EVAP CANISTER VENT CONTROL VALVE-I
1. Turn ignition switch OFF.
2. Remove EVAP canister vent c ontrol valve from EVAP canister.
3. Check portion (A) of EVAP canister vent control valve for rust.
Is it rusted?
YES >> Replace EVAP canister vent control valve. Refer to FL-
10, "Exploded View".
NO >> GO TO 2.
2.CHECK EVAP CANISTER VENT CONTROL VALVE-II
WITH CONSULT-III
1. Reconnect harness connectors disconnected.
2. Turn ignition switch ON.
3. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
4. Check air passage continuity and operation delay time. Check that new O-ring is installed properly.
Operation takes less than 1 second.
WITHOUT CONSULT-III
1. Disconnect EVAP canister vent control valve harness connector.
2. Check air passage continuity and operation delay time under the following conditions. Check that new O-ring is installed properly.
Operation takes less than 1 second.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace EVAP canister vent control valve. Refer to FL-10, "
Exploded View".
3.CHECK EVAP CANISTER VENT CONTROL VALVE-III
WITH CONSULT-III
1. Clean the air passage [portion (A) to (B)] of EVAP canister vent control valve using an air blower.
2. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
JSBIA0693ZZ
VENT CONTROL/V Condition Air passage continuity between (A) and (B)
ON Not existed
OFF Existed
JSBIA0694ZZ
Condition Air passage continuity between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Not existed
OFF Existed
Revision: 2010 May2011 QX56

EC-328
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0447 EVAP CANISTER VENT CONTROL VALVE
3. Check air passage continuity and operation delay time.
Check that new O-ring is installed properly.
Operation takes less than 1 second.
WITHOUT CONSULT-III
1. Clean the air passage [portion (A) to (B)] of EVAP canister vent control valve using an air blower.
2. Check air passage continuity and operation delay time under the following conditions. Check that new O-ring is installed properly.
Operation takes less than 1 second.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace EVAP canister vent control valve. Refer to FL-10, "
Exploded View".
VENT CONTROL/V Condition Air passage continuity between (A) and (B)
ON Not existed
OFF Existed
JSBIA0694ZZ
Condition Air passage continuity between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Not existed
OFF Existed
Revision: 2010 May2011 QX56

P0448 EVAP CANISTER VENT CONTROL VALVEEC-331
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Component Inspection (EVAP C
anister Vent Control Valve)INFOID:0000000006288362
1.CHECK EVAP CANISTER VENT CONTROL VALVE-I
1. Turn ignition switch OFF.
2. Remove EVAP canister vent c ontrol valve from EVAP canister.
3. Check portion (A) of EVAP canister vent control valve for rust.
Is it rusted?
YES >> Replace EVAP canister vent control valve. Refer to FL-
10, "Exploded View".
NO >> GO TO 2.
2.CHECK EVAP CANISTER VENT CONTROL VALVE-II
WITH CONSULT-III
1. Reconnect harness connectors disconnected.
2. Turn ignition switch ON.
3. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
4. Check air passage continuity and operation delay time. Check that new O-ring is installed properly.
Operation takes less than 1 second.
WITHOUT CONSULT-III
1. Disconnect EVAP canister vent control valve harness connector.
2. Check air passage continuity and operation delay time under the following conditions. Check that new O-ring is installed properly.
Operation takes less than 1 second.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace EVAP canister vent control valve. Refer to FL-10, "
Exploded View".
3.CHECK EVAP CANISTER VENT CONTROL VALVE-III
WITH CONSULT-III
1. Clean the air passage [portion (A) to (B)] of EVAP canister vent control valve using an air blower.
2. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
JSBIA0693ZZ
VENT CONTROL/V Condition Air passage continuity between (A) and (B)
ON Not existed
OFF Existed
JSBIA0694ZZ
Condition Air passage continuity between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Not existed
OFF Existed
Revision: 2010 May2011 QX56

EC-332
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0448 EVAP CANISTER VENT CONTROL VALVE
3. Check air passage continuity and operation delay time.
Check that new O-ring is installed properly.
Operation takes less than 1 second.
WITHOUT CONSULT-III
1. Clean the air passage [portion (A) to (B)] of EVAP canister vent control valve using an air blower.
2. Check air passage continuity and operation delay time under the following conditions. Check that new O-ring is installed properly.
Operation takes less than 1 second.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace EVAP canister vent control valve. Refer to FL-10, "
Exploded View".
VENT CONTROL/V Condition Air passage continuity between (A) and (B)
ON Not existed
OFF Existed
JSBIA0694ZZ
Condition Air passage continuity between (A) and (B)
12 V direct current supply between
terminals 1 and 2 Not existed
OFF Existed
Revision: 2010 May2011 QX56

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOREC-333
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0451 EVAP CONTROL SYSTEM
PRESSURE SENSOR
DTC LogicINFOID:0000000006288316
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and wait at least 40 seconds. NOTE:
Do not depress accelerator pedal even slightly.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-333, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288317
1.CHECK EVAP CONTRO L SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check that water is not inside connectors.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace harness connector.
2.CHECK EVAP CONTROL SYS TEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check the voltage between EVAP control system pressure sensor harness connector and ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis con- tent) DTC detecting condition Possible cause
P0451 EVAP SYS PRES SEN
(EVAP control system
pressure sensor perfor-
mance) ECM detects a sloshing signal
from the EVAP control system
pressure sensor  (EVAP control system pressure sensor circuit is shorted.)
Harness or connectors
(Battery current sensor circuit is open or shorted.)
(Accelerator pedal position sensor 2 circuit is shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Crankshaft position sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Battery current sensor
 Accelerator pedal position sensor
 Camshaft position sensor (bank 1)
 Crankshaft position sensor
 Refrigerant pressure sensor
EVAP control system
pressure sensor Ground Voltage (V)
Connector Terminal
C17 3 Ground Approx. 5 V
Revision: 2010 May2011 QX56