air condition INFINITI QX56 2011 Factory Service Manual

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

P0452 EVAP CONTROL SYSTEM PRESSURE SENSOREC-339
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 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
11 .CHECK EVAP CONTROL SYSTEM PRESSURE SENS OR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Check the continuity between EVAP control syst em pressure sensor harness connector and ECM har-
ness connector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 12.
12.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between EVAP c ontrol system pressure sensor and ECM
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
13.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-335, "
Component Inspection (EVAP Control System Pressure Sensor)".
Is the inspection result normal?
YES >> GO TO 14.
NO >> Replace EVAP control system pressure sensor. Refer to FL-10, "
Exploded View".
14.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (EVAP Cont rol System Pressure Sensor)INFOID:0000000006288363
1.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Turn ignition switch OFF.
2. Remove EVAP control system pressure sensor with its harness connector. Always replace O-ring with a new one.
3. Install a vacuum pump to EVAP control system pressure sensor.
4. Turn ignition switch ON and check output voltage between ECM harness connector terminals under the following conditions.
CAUTION:
 Always calibrate the vacuum pu mp gauge when using it.
EVAP control system
pressure sensor ECM
Continuity
Connector Terminal Connector Terminal
C17 2 E80 143 Existed
ECM Condition
[Applied vacuum kPa (kg/cm
2, psi)] Voltage (V)
Connector +–
Terminal Terminal
E80 143 150 Not applied 1.8 - 4.8
-26.7 (-0.272, -3.87) 2.1 to 2.5 lower than above value
Revision: 2010 May2011 QX56

P0453 EVAP CONTROL SYSTEM PRESSURE SENSOREC-345
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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2. Check if water will drain from the EVAP canister (1).
- EVAP canister vent control valve (2)
Does water drain from EVAP canister?
YES >> GO TO 17.
NO >> GO TO 19.
17.CHECK EVAP CANISTER
Weigh the EVAP canister with the EV AP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
Is the inspection result normal?
YES >> GO TO 19.
NO >> GO TO 18.
18.DETECT MALFUNCTIONING PART
Check the following.
 EVAP canister for damage
 EVAP hose between EVAP canister and vehi cle frame for clogging or poor connection
>> Repair hose or replace EVAP canister. Refer to FL-10, "
Hydraulic Layout".
19.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (EVAP Cont rol System Pressure Sensor)INFOID:0000000006288365
1.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Turn ignition switch OFF.
2. Remove EVAP control system pressure sensor with its harness connector. Always replace O-ring with a new one.
3. Install a vacuum pump to EVAP control system pressure sensor.
4. Turn ignition switch ON and check output voltage between ECM harness connector terminals under the following conditions.
CAUTION:
 Always calibrate the vacuum pu mp gauge when using it.
 Never apply below -93.3 kPa (-0.952 kg/cm
2, -13.53 psi) or pressure over 101.3 kPa (1.033 kg/cm2,
14.69 psi).
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace EVAP control system pressure sensor.
JSBIA0692ZZ
ECM Condition
[Applied vacuum kPa (kg/cm
2, psi)] Voltage (V)
Connector +–
Terminal Terminal
E80 143 150 Not applied 1.8 - 4.8
-26.7 (-0.272, -3.87) 2.1 to 2.5 lower than above value
Revision: 2010 May2011 QX56

EC-358
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0506 ISC SYSTEM
P0506 ISC SYSTEM
DescriptionINFOID:0000000006217861
The ECM controls the engine idle speed to a specified leve
l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor detects the
actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration and engine load (air conditioner, power steering and cooling fan
operation, etc.).
DTC LogicINFOID:0000000006217862
DTC DETECTION LOGIC
NOTE:
If DTC P0506 is displayed with ot her DTC, first perform the trouble diagnosis for the other DTC.
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.
If the target idle speed is ou t of the specified value, perform EC-148, "
Work Procedure", before con-
ducting DTC Confirmation Procedure.
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
 Always perform the test at a temperature above −10 °C (14 °F).
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and run it for at least 1 minute at idle speed.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-358, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217863
1.CHECK INTAKE AIR LEAKAGE
1. Start engine and let it idle.
2. Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Discover air leakage location and repair.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0506 ISC SYSTEM
(Idle speed control system
RPM lower than expected) The idle speed is less than the target idle
speed by 100 rpm or more.
 Electric throttle control actuator
 Intake air leakage
Revision: 2010 May2011 QX56

EC-360
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0507 ISC SYSTEM
P0507 ISC SYSTEM
DescriptionINFOID:0000000006217864
The ECM controls the engine idle speed to a specified leve
l through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric thrott le control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idli ng speed. The crankshaft position sensor detects the
actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is t he lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration and engine load (air conditioner, power steering and cooling fan
operation, etc.).
DTC LogicINFOID:0000000006217865
DTC DETECTION LOGIC
NOTE:
If DTC P0507 is displayed with ot her DTC, first perform the trouble diagnosis for the other DTC.
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.
If the target idle speed is ou t of the specified value, perform EC-148, "
Work Procedure", before con-
ducting DTC Confirmation Procedure.
TESTING CONDITION:
 Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
 Always perform the test at a temperature above −10 °C (14 °F).
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and run it for at least 1 minute at idle speed.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-360, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217866
1.CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0507 ISC SYSTEM
(Idle speed control system
RPM higher than expected) The idle speed is more than the target idle
speed by 200 rpm or more.  Electric throttle control actuator
 Intake air leakage
 PCV system
Revision: 2010 May2011 QX56

EC-362
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P050E COLD START CONTROL
P050E COLD START CONTROL
DescriptionINFOID:0000000006288336
ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.
This control promotes the activation of three way ca
talyst by heating the catalyst and reduces emissions.
DTC LogicINFOID:0000000006288337
DTC DETECTION LOGIC
NOTE:
If DTC P050E is displayed with other DTC, first perform the trouble diagnosis for other DTC.
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check the indication of “COOLAN TEMP/S”.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the value of
“COOLAN TEMP/S” between 5°C (41°F) and 36°C (97°F)?
YES >> GO TO 3.
NO-1 [If it is below 5 °C (41 °F)]>>Warm up the engine until the val ue of “COOLAN TEMP/S” reaches 5°C
(41 °F) or more. Retry from step 1.
NO-2 [If it is above 36 °C (97 °F)]>>Cool engine down to less than 36 °C (97 °F). Retry from step 1.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
WITH CONSULT-III
1. Set the select lever in N range.
2. Start the engine and warm up in idle with the value of “COOLAN TEMP/S” between 5 °C (41 °F) and 40 °C
(104 °F) for more than 15 seconds.
3. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-362, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288338
1.PERFORM IDLE AIR VOLUME LEARNING
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P050E Cold start engine exhaust temper-
ature too low The temperature of the catalyst inlet does not
rise to the proper temperature when the engine
is started with pre-warming up condition.  Lack of intake air volume
 Fuel injection system
ECM
Revision: 2010 May2011 QX56

P0527 COOLING FAN SPEED SENSOREC-369
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Is inspection result normal?
YES >> Check intermittent incident. Refer to
GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
6.CHECK COOLING FAN SPEED SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between electrically-contro lled cooling fan coupling harness connector and ECM har-
ness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK COOLING FAN SPEED SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform cooling fan speed sensor component inspection. Refer to EC-369, "
Component Inspection (Cool-
ing Fan Speed Sensor)".
Is inspection result normal?
YES >> GO TO 8.
NO >> Replace electrically-controlled cooling fan coupling.
8.CHECK COOLING FAN ROTATIONAL CONDITION
Rotate the cooling fan by hand.
Dose the cooling fan rotates smoothly?
YES >> GO TO 9.
NO >> Check that the cooling fan is not interfered with other parts.
9.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING SYSTEM
Refer to EC-495, "
Diagnosis Procedure".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (C ooling Fan Speed Sensor)INFOID:0000000006217869
1.CHECK COOLING FAN SPEED SENSOR
1. Turn ignition switch OFF.
2. Disconnect electrically-controlled c ooling fan coupling harness connector.
3. Rotate the electrically-controlled cooling fan coupling slowly with hand and check the voltage between
electrically-controlled cooling fan coupling c onnector terminals under the following conditions.
+
−Continuity
ECM
Connector Terminal F 111 1 0 Ground Existed
E80 174
175
+
−
Continuity
Electrically-controlled cooling fan
coupling ECM
Connector Terminal Connector Terminal F39 5 F111 37 Existed
Revision: 2010 May2011 QX56