2011 INFINITI QX56 ground

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-341
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P0453 EVAP CONTROL SYSTEM
PRESSURE SENSOR
DTC LogicINFOID:0000000006288322
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.
TESTING CONDITION:
Always perform test at a temperature of 5 °C (41 °F) or more.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Select “DATA MONITOR” mode with CONSULT-III.
7. Check that “FUEL T/TM P SE” is more than 0°C (32 °F).
8. Start engine and wait at least 20 seconds.
9. Check 1st trip DTC.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes to ECM harness connector terminals under the following conditions.
3. Check that the voltage is less than 4.2 V.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0453 EVAP SYS PRES SEN
(EVAP control system pres-
sure sensor high input) An excessively high voltage
from the sensor is sent to
ECM.  Harness or connectors
(EVAP control system pressure sensor circuit is short-
ed.)
(Crankshaft position sensor circuit is open or shorted.)
[Camshaft position sensor (bank 1) circuit is shorted.]
(Accelerator pedal position sensor 2 circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is shorted.)
 EVAP control system pressure sensor
 Crankshaft position sensor
 Camshaft position sensor (bank 1)
 Accelerator pedal position sensor 2
 Battery current sensor
 Refrigerant pressure sensor
 EVAP canister vent control valve
 EVAP canister
 Rubber hose from EVAP canister vent control valve to
vehicle frame
ECM Ground
Connector +–
Terminal Terminal
E80 134
(Fuel tank temperature sensor signal) 175
Revision: 2010 May2011 QX56

EC-342
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P0453 EVAP CONTROL S
YSTEM PRESSURE SENSOR
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON.
6. Turn ignition switch OFF and wait at least 10 seconds.
7. Start engine and wait at least 20 seconds.
8. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-342, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288323
1.CHECK EVAP CONTROL 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 SY STEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check the voltage between EVAP control syst em pressure sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 3.
3.CHECK EVAP CONTROL SYST EM PRESSURE SENSOR POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between EVAP control system pressure sensor harness connector and ECM har-
ness connector.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open between ECM and EVAP control system pressure sensor
 Loose or poor connection for each connector and harness
>> Repair open circuit.
5.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.
EVAP control system pressure sensor Ground Voltage (V)
Connector Terminal
C17 3 Ground Approx. 5
EVAP control system pressure sensor ECM Continuity
Connector Terminal Connector Terminal
C17 3 E80 133 Existed
Revision: 2010 May2011 QX56

P0453 EVAP CONTROL SYSTEM PRESSURE SENSOREC-343
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Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair short to ground or short to power in harness or connectors.
6.CHECK COMPONENTS
Check the following.
 Crankshaft position sensor (Refer to EC-301, "
Component Inspection (Crankshaft Position Sensor)".)
 Camshaft position sensor (bank 1) (Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".)
 Battery current sensor (Refer to EC-427, "
Component Inspection (Battery Current Sensor)".)
 Refrigerant pressure sensor (Refer to EC-520, "
Component Function Check".)
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace malfunctioning component.
7.CHECK APP SENSOR
Refer to EC-470, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 19.
NO >> GO TO 8.
8.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly.
Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSI ST SYSTEM : Removal and Installation"
(Without distance control assist system)
Refer to ACC-4, "
MODELS WITH DISTANCE CONTROL ASSI ST SYSTEM : Removal and Installation" (With
distance control assist system).
>> INSPECTION END
9.CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between EVAP control syst em pressure sensor harness connector and ECM har-
ness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 11.
NO >> GO TO 10.
ECM Sensor
Connector Terminal Name Connector Terminal
F110 76 Crankshaft position sensor F74 1
77 Camshaft position sensor (bank 1) F84 1
E80 133EVAP control system pressure sen-
sor
C17 3
Battery current sensor E63 2
Refrigerant pressure sensor E77 1
131 APP sensor 2 (Without ICC) E110 1
APP sensor 2 (with ICC) E67 9
EVAP control system
pressure sensor ECM
Continuity
Connector Terminal Connector Terminal
C17 1 E80 150 Existed
Revision: 2010 May2011 QX56

EC-344
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P0453 EVAP CONTROL S
YSTEM PRESSURE SENSOR
10.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between EVAP control 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.
11 .CHECK EVAP CONTROL SYSTEM PRESSURE SEN SOR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Check the continuity between EVAP control system 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 control 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 RUBBER TUBE
1. Disconnect rubber tube connected to EVAP c anister vent control valve. Refer to FL-10, "
Hydraulic Lay-
out".
2. Check the rubber tube for clogging.
Is the inspection result normal?
YES >> GO TO 14.
NO >> Clean the rubber tube using an air blower, repair or replace rubber tube.
14.CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-327, "
Component Inspection (EVAP Canister Vent Control Valve)".
Is the inspection result normal?
YES >> GO TO 15.
NO >> Replace EVAP canister vent control valve. Refer to FL-10, "
Exploded View".
15.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 16.
NO >> Replace EVAP control system pressure sensor. Refer to FL-10, "
Exploded View".
16.CHECK IF EVAP CANISTER IS SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
EVAP control system
pressure sensor ECM
Continuity
Connector Terminal Connector Terminal
C17 2 E80 143 Existed
Revision: 2010 May2011 QX56

EC-368
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P0527 COOLING FAN SPEED SENSOR
2.CHECK COOLING FAN SPEED SENSOR POWER SUPPLY CIRCUIT-II
1. Check the voltage between electrically-controlled cooling fan coupling harness connector and the ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK COOLING FAN SPEED SENSOR GROUND 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.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ECM harness connector and the ground.
+
−Vol tag e
(Approx.)
Electrically-controlled cooling fan coupling
Connector terminalF39 2 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Low fuel pressure sensor F25 3
Power steering pressure sensor F35 1
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
Electrically-controlled cooling fan
coupling ECM
Connector Terminal Connector Terminal F 3 9 4 F 111 4 5 E x i s t e d
Revision: 2010 May2011 QX56

P0527 COOLING FAN SPEED SENSOREC-369
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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

EC-370
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P0527 COOLING FAN SPEED SENSOR
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace Electrically-controlled cooling fan coupling.
+
−
Condition Voltage (V)
(Approx.)
Electrically-controlled
cooling fan coupling
Te r m i n a l
54  5V direct current supply to terminal 2
 Terminal 4 connect to ground 0
⇔ 5
NOTE:
The voltage is in waveform
Revision: 2010 May2011 QX56