2011 INFINITI QX56 Cooling

EC-370
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
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

P0550 PSP SENSOREC-371
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0550 PSP SENSOR
DTC LogicINFOID:0000000006217870
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 let it idle for at least 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-371, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217871
1.CHECK POWER STEERING PRESSURE SENSOR POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect power steering pressure (PSP) sensor harness connector.
3. Turn ignition switch ON.
4. Check the voltage between PSP sensor harness connector terminals.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK POWER STEERING PRESSURE SENSOR POWER SUPPLY CIRCUIT-II
1. Check the voltage between PSP sensor harness connector and the ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0550 PW ST P SEN/CIRC
(Power steering pressure
sensor circuit) An excessively low or high voltage from the
sensor is sent to ECM.  Harness or connectors
(The Fuel rail pressure sensor circuit is
open or shorted.)
(The Power steering pressure sensor cir-
cuit is open or shorted)
(The Electrically-controlled cooling fan
coupling circuit is open or shorted)
 Fuel rail pressure sensor
 Power steering pressure sensor
 Electrically-controlled cooling fan cou- pling
PSP sensor Vo l ta g e
(Approx.)
Connector +
−
terminal
F35 1 3 5 V
Revision: 2010 May2011 QX56

EC-372
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0550 PSP SENSOR
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 PSP SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between PSP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the 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.
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
+
−Voltag e
(Approx.)
PSP sensor
Connector terminal F35 1 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
PSP sensor ECM
Connector Terminal Connector Terminal F35 3 F111 45 Existed
+ −Continuity
ECM
Connector Terminal F 111 1 0 Ground Existed
E80 174
175
Revision: 2010 May2011 QX56

EC-400
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1217 ENGINE OVER TEMPERATURE
P1217 ENGINE OVER TEMPERATURE
DTC LogicINFOID:0000000006217909
DTC DETECTION LOGIC
NOTE:

If DTC P1217 is displayed with DTC UXXXX, perform the trouble diagnosis for DTC UXXXX.
 If DTC P1217 is displayed with DTC P0607, perfo rm the trouble diagnosis for DTC P0607. Refer to
EC-378, "
DTC Logic".
 If DTC P1217 is displayed with DTC P0527, perfo rm the trouble diagnosis for DTC P0527. Refer to
EC-367, "
DTC Logic".
If the cooling fan or any of other components in the cooling system has a malfunction, engine coolant temper-
ature increases.
When the engine coolant temperature reaches an abnorma lly high temperature condition, a malfunction is
indicated.
CAUTION:
When a malfunction is indicated, al ways replace the coolant. Refer to CO-8, "
Draining" and CO-9,
"Refilling". Also, replace the engine oil. Refer to LU-8, "Draining" and LU-8, "Refilling".
1. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Always use
coolant with the proper mixture ratio. Refer to MA-11, "
Anti-Freeze Coolant Mixture Ratio".
2. After refilling coolant, run engine to en sure that no water-flow noise is emitted.
DTC CONFIRMATION PROCEDURE
1.PERFORM COMPONENT FUNCTION CHECK
Perform component function check. Refer to EC-400, "
Component Function Check".
NOTE:
Use component function check to check the overall functi on of the cooling fan. During this check, a DTC might
not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-401, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006217910
1.PERFORM COMPONENT FUNCTION CHECK-I
WARNING:
Never remove the reservoir tank cap when the engi ne is hot. Serious burns could be caused by high
pressure fluid escaping from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by turning it a quarter turn to allow built-up
pressure to escape. Then turn the cap all the way off.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1217 Engine over temperature
(Overheat)  Cooling fan does not operate properly
(Overheat).
 Cooling fan system does not operate properly (Overheat).
 Engine coolant is not within the specified quantity.  Harness or connectors
(The cooling fan circuit is open or shorted.)
 IPDM E/R
 Electrically-controlled cooling fan coupling
 Cooling fan speed sensor
 Radiator hose
Radiator
 Reservoir tank cap
 Water pump
Thermostat
Revision: 2010 May2011 QX56

P1217 ENGINE OVER TEMPERATUREEC-401
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Check the coolant level in the reservoir tank and radiator.
Allow engine to cool befo
re checking coolant level.
Is the coolant level in the reservoir tank and/or radiator below the
proper range?
YES >> Proceed to EC-401, "Diagnosis Procedure".
NO >> GO TO 2.
2.PERFORM COMPONENT FUNCTION CHECK-II
Confirm whether customer filled the coolant or not.
Did customer fill the coolant?
YES >> Proceed to EC-401, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM COMPONENT FUNCTION CHECK-III
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage. NOTE:
Fan speed changes as the percentage changes.
WITHOUT CONSULT-III
1. Start the engine.
2. Perform IPDM E/R auto active test. Refer to PCS-10, "
Diagnosis Description".
3. Check that cooling fan speed increase. NOTE:
Speed changes gradually when performing the auto active test.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-401, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217911
1.CHECK COOLING FAN OPERATION
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage. NOTE:
Speed changes gradually as the percentage changes.
WITHOUT CONSULT-III
1. Stert the engine.
2. Perform IPDM E/R auto active test and check cooling fan operation, refer to PCS-10, "
Diagnosis Descrip-
tion".
3. Check that cooling fan speed increase.
NOTE:
Speed changes gradually when performing the auto active test.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Proceed to EC-495, "
Diagnosis Procedure".
2.CHECK ENGINE COOLANT LEAKAGE-I
Check cooling system for leakage. Refer to CO-8, "
Inspection".
Is leakage detected?
SEF621W
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-483
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
DTC LogicINFOID:0000000006288355
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:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 60 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-483, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288356
1.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect low fuel pressure sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between low fuel pressure sensor harness connector terminals.
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-II
Check the voltage between low fuel pressure sensor harness connector and the ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2539 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input and high in-
put) Signal voltage from the low fuel pressure
sensor remains at more than 4.84 V / less
than 0.3 V for 5 seconds or more.  Harness or connectors
(Low fuel pressure sensor circuit is open
or shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Cooling fan speed sensor circuit is open
or shorted.)
(FRP sensor circuit is open or shorted.)
 Low fuel pressure sensor
 Power steering pressure sensor
 Cooling fan speed sensor
 FRP sensor
P2541
LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input) Signal voltage from the low fuel pressure
sensor remains at less than 0.49 V for 5 sec-
onds or more.
P2542 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit high input) Signal voltage from the low fuel pressure
sensor remains at more than 4.1 V for 5 sec-
onds or more.
Low fuel pressure sensor
Vo l ta g e
(Approx.)
Connector +
−
terminal
F25 3 1 5 V
Revision: 2010 May2011 QX56

EC-484
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
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 LOW FUEL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between low fuel pressu re sensor harness connector and ECM harness 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.
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
+
−Voltag e
(Approx.)
Low fuel pressure sensor
Connector Terminal F25 3 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Power steering pressure sensor F35 1
Low fuel pressure sensor F25 3
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
Low fuel pressure sensor ECM
Connector Terminal Connector Terminal F25 1 F111 45 Existed
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
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Revision: 2010 May2011 QX56

ELECTRICALLY-CONTROLLED COOLING FAN COUPLINGEC-495
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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ELECTRICALLY-CONTROLLED COOLING FAN COUPLING
Component Function CheckINFOID:0000000006217997
1.CHECK COOLING FAN FUNCTION
WITH CONSULT-III
1. Start the engine.
2. Perform “FAN DUTY CONTROL” in “ACTIVE TEST” mode with CONSULT-III.
3. Check that cooling fan speed varies according to the percentage.
NOTE:
Speed changes gradually as the percentage changes.
WITHOUT CONSULT-III
1. Start the engine and warm up the engine until engine coolant temperature reaches at least 98°C (209 °F).
2. Check that cooling fan speed increase.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to EC-495, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217998
1.CHECK DRIVE BELT
1. Turn ignition switch OFF.
2. Check that the drive belt is not broken.
Is inspection result normal?
YES >> GO TO 2.
NO >> Replace drive belt.
2.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING POWER SUPPLY
1. Disconnect electrically-controlled c ooling fan coupling harness connector.
2. Turn ignition switch ON.
3. Check the voltage between electrically-controll ed cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for power supply circuit.
3.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check the continuity between electrically-cont rolled cooling fan coupling harness connector and ground.
Is inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK ELECTRICALLY-CONTROLLED COOLING FAN COUPLING CONTROL SIGNAL
WITH CONSULT-III
+ −Vo l ta g e
(Approx.)
Electrically-controlled cooling fan coupling
Connector TerminalF39 1 Ground Battery voltage
+ −Continuity
Electrically-controlled cooling fan coupling
Connector TerminalF39 6 Ground Existed
Revision: 2010 May2011 QX56