engine coolant INFINITI QX56 2010 Factory Workshop Manual

P0125 ECT SENSOREC-131
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1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
2. If NG, replace engine coolant temperature sensor.
PBIB2005E
Engine coolant temperature °C ( °F)] Resistance (kΩ)
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
Revision: April 20092010 QX56

EC-132
< COMPONENT DIAGNOSIS >[VK56DE]
P0127 IAT SENSOR
P0127 IAT SENSOR
Component DescriptionINFOID:0000000005149146
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a
thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000005149147
DTC Confirmation ProcedureINFOID:0000000005149148
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
1. Wait until engine coolant temperature is less than 96 °C (205 °F)
a. Turn ignition switch ON.
b. Select “DATA MONITOR” mode with CONSULT-III.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 96 °C (205 °F), turn ignition switch OFF and cool down
engine.
• Perform the following steps before engine coolant temperature is above 96 °C (205° F).
BBIA0355E
Intake air temperature
°C ( °F)] Voltage* (V)
Resistance (kΩ)
25 (77) 3.31.800 - 2.200
80 (176) 1.20.283 - 0.359
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127 Intake air temperature
too high Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor. • Harness or connectors
(The sensor circuit is open or shorted)
• Intake air temperature sensor
Revision: April 20092010 QX56

P0128 THERMOSTAT FUNCTIONEC-135
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P0128 THERMOSTAT FUNCTION
On Board Diagnosis LogicINFOID:0000000005149151
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301,
P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diag nosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to EC-192, "
DTC Confirmation Procedure".
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureINFOID:0000000005167702
WITH CONSULT-III
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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:
• For best results, perform at ambient temperature of –10 °C (14° F) or higher.
• For best results, perform at engine coolant temperature of –10 °C (14° F) to 56 °C (133° F).
• Before performing the following pro cedure, do not fill with the fuel.
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DAT A MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”. If it is below 56 °C (133 °F), go to following step.
If it is above 56 °C (133° F), cool down the engine to less than 56° C (133°F). Then go to next steps.
6. Start engine.
7. Drive vehicle for 10 consecutive minutes under the following conditions.
If “COOLAN TEMP/S” increases to more than 75° C (167°F) within 10 minutes, turn ignition switch
OFF because the test result will be OK.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-135, "
DTC Confirmation Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149153
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-136, "
Component Inspection".
OK or NG
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 Thermostat function The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough. •Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor
VHCL SPEED SE More than 56 km/h (35 MPH)
Revision: April 20092010 QX56

EC-136
< COMPONENT DIAGNOSIS >[VK56DE]
P0128 THERMOSTAT FUNCTION
2.CHECK THERMOSTAT
Refer to CO-22, "
Removal and Installation".
OK or NG
OK >> INSPECTION END
NG >> Replace thermostat.
Component InspectionINFOID:0000000005149154
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor terminals 1 and 2 as shown in the figure.
2. If NG, replace engine coolant temperature sensor.
PBIB2005E
Engine coolant temperature °C ( °F)] Resistance (k Ω)
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
Revision: April 20092010 QX56

EC-182
< COMPONENT DIAGNOSIS >[VK56DE]
P0181 FTT SENSOR
P0181 FTT SENSOR
Component DescriptionINFOID:0000000005149196
The fuel tank temperature sensor
is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a the rmistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 107 (Fuel
tank temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000005149197
DTC Confirmation ProcedureINFOID:0000000005149198
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.
WITH CONSULT-III
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
If 1st trip DTC is detected, go to EC-183, "
Diagnosis Procedure".
If 1st trip DTC is not detected, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check “COOLAN TEMP/S” value. If the “COOLAN TEMP/S” is less than 60 °C (140° F), the result will be OK.
If the “COOLAN TEMP/S” is above 60 °C (140° F), go to the following step.
5. Cool engine down until “COOLAN TEMP/S” signal is less than 60 °C (140° F).
BBIA0583E
Fluid temperature
°C ( °F)] Voltage*
(V) Resistance
(kΩ)
20 (68) 3.52.3 - 2.7
50 (122) 2.20.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0181
0181 Fuel tank temperature
sensor circuit range/per-
formance Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signals
from engine coolant temperature sensor and in-
take air temperature sensor.
• Harness or connectors
(The sensor circuit is open or shorted)
• Fuel tank temperature sensor
Revision: April 20092010 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-193
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c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Restart engine and let it idle for about 15 minutes.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-193, "
Diagnosis Procedure".
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
d. Start engine and drive the vehicle under the similar conditi ons to (1st trip) Freeze Frame Data for a certain
time. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
The time to driving varies according to the engine speed in the freeze frame data.
Diagnosis ProcedureINFOID:0000000005149213
1.CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2.CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace it.
3.PERFORM POWER BALANCE TEST
With CONSULT-III
1. Perform “POWER BALANCE ” in “ACTIVE TEST” mode.
2. Is there any cylinder which does not produce a momentary engine speed drop?
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Basic fuel schedule Basic fuel schedule in freeze frame data × (1 ± 0.1)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 ° C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Engine speed Time
Around 1,000 rpm Approximately 10 minutes
Around 2,000 rpm Approximately 5 minutes
More than 3,000 rpm Approximately 3.5 minutes
Revision: April 20092010 QX56

P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-225
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P0443 EVAP CANISTER PURGE VOLU
ME CONTROL SOLENOID VALVE
DescriptionINFOID:0000000005149242
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoi d valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engi ne control. The optimum value stored in the ECM is
determined by considering various engine conditions. When t he engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
On Board Diagnosis LogicINFOID:0000000005167699
Sensor Input signal to ECMECM functionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor
Engine coolant temperature
Battery Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor Vehicle speed*
2
PBIB2057E
DTC No.Trouble diagnosis
name DTC detecting condition
Possible cause
P0443
0443 EVAP canister purge
volume control sole-
noid valve A)
The canister purge flow is detected during the
vehicle is stopped while the the engine is run-
ning, even when EVAP canister purge volume
control solenoid valve is completely closed. • EVAP control system pressure sensor
• EVAP canister purge volume control so-
lenoid valve
(The valve is stuck open.)
• EVAP canister vent control valve
• EVAP canister
• Hoses (Hoses are connected incorrectly or
clogged.)
B)
The canister purge flow is detected during the
specified driving conditions, even when EVAP
canister purge volume control solenoid valve
is completely closed.
Revision: April 20092010 QX56

EC-226
< COMPONENT DIAGNOSIS >[VK56DE]
P0443 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
DTC Confirmation Procedure
INFOID:0000000005167700
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.
PROCEDURE FOR MALFUNCTION A
TESTING CONDITION:
• Perform “DTC CONFIRMATION PROCEDURE” when the fuel level is between 1/4 and 3/4 full, and
vehicle is placed on flat level surface.
• Always perform test at a temperature of 5 to 60 °C (41° F).
• Cool the vehicle so that engine coolant temperature becomes same level as ambient temperature.
With CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Check that the following condition are met.
FUEL T/TMP SE: 0 – 35 °C (32 – 95° F)
3. Start engine and wait at least 60 seconds.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-227, "
Diagnosis Procedure".
With GST
1. Turn ignition switch ON.
2. Set voltmeter probes to ECM terminal 107 (FTT sensor signal)
and ground.
3. Check that the voltage is 3.1 – 4.2 V.
4. Start engine and wait at least 60 seconds.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-227, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION B
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
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.
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 “PURG VOL CN/V P1444” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-III.
7. Touch “START”.
JMBIA2925ZZ
Revision: April 20092010 QX56

P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-231
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P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VA LV E
DescriptionINFOID:0000000005149247
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from
the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoi d valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engi ne control. The optimum value stored in the ECM is
determined by considering various engine conditions. When t he engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
On Board Diagnosis LogicINFOID:0000000005149248
Sensor Input signal to ECMECM functionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
1
EVAP canister
purge flow controlEVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor
Engine coolant temperature
Battery Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor Vehicle speed*
2
PBIB2057E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0444
0444 EVAP canister purge volume
control solenoid valve circuit
open An excessively low voltage signal is sent
to ECM through the valve • Harness or connectors
(The solenoid valve circuit is open or
shorted.)
• EVAP canister purge volume control so-
lenoid valve
P0445
0445 EVAP canister purge volume
control solenoid valve circuit
shorted An excessively high voltage signal is sent
to ECM through the valve • Harness or connectors
(The solenoid valve circuit is shorted.)
• EVAP canister purge volume control so-
lenoid valve
Revision: April 20092010 QX56

EC-302
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
P1217 ENGINE OVER TEMPERATURE
On Board Diagn
osis LogicINFOID:0000000005149350
NOTE:
•If DTC P1217 is displayed with DTC UXXXX, first perform the trouble diagnosis for DTC UXXXX.
• If DTC P1217 is displayed with DTC P0607, first perform the trouble diagno sis for DTC P0607. Refer
to EC-288
.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnorma lly high temperature condition, a malfunction is
indicated.
This self-diagnosis has the one trip detection logic.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant. Refer to CO-11, "
Changing Engine
Coolant". Also, replace the engine oil. Refer to LU-9, "Changing Engine Oil".
1. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to use coolant with the proper mixture ratio. Refer to CO-10
.
2. After refilling coolant, run engine to en sure that no water-flow noise is emitted.
Overall Function CheckINFOID:0000000005149351
Use this procedure to check the overall function of the cooling fan. During this check, a DTC might not be con-
firmed.
WARNING:
Never remove the radiator cap and/or reservoir tank cap when the engine is hot. Serious burns could
be caused by high pressure fluid escaping fr om the radiator and/or reservoir tank.
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.
WITH CONSULT-III
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to EC-392,
"Diagnosis Procedure".
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-392,
"Diagnosis Procedure".
3. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1217
1217 Engine over tempera-
ture (Overheat) • Cooling fan does not operate properly (Over-
heat).
• Cooling fan system does not operate proper- ly (Overheat).
• Engine coolant was not added to the system using the proper filling method.
• Engine coolant is not within the specified
range. • Harness or connectors
(The cooling fan circuit is open or short-
ed.)
• Cooling fan
• Cooling fan (crankshaft driven)
• IPDM E/R (Cooling fan relay)
•Radiator hose
•Radiator
•Radiator cap
• Reservoir tank
• Reservoir tank cap
• Water pump
•Thermostat
For more informat ion, refer to EC-304,
"Main 13 Causes of Overheating".
SEF621W
Revision: April 20092010 QX56