2011 INFINITI QX56 engine overheat

CO-1
ENGINE
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CONTENTS
ENGINE COOLING SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
PREPARATION ............................................3
PREPARATION .............................................. .....3
Commercial Service Tools ................................. ......3
SYSTEM DESCRIPTION ..............................4
DESCRIPTION ............................................... .....4
Engine Cooling System ..................................... ......4
Engine Cooling System Schematic .........................5
SYMPTOM DIAGNOSIS ...............................6
OVERHEATING CAUSE ANALYSIS ............. .....6
Troubleshooting Chart ........................................ ......6
PERIODIC MAINTENANCE ..........................8
ENGINE COOLANT ....................................... .....8
Inspection ............................................................ ......8
Draining .....................................................................8
Refilling .....................................................................9
Flushing ...................................................................10
RADIATOR .........................................................11
RESERVOIR TANK CAP ..........................................11
RESERVOIR TANK CAP : Inspection ................. ....11
RADIATOR ............................................................. ....11
RADIATOR : Inspection ...........................................11
REMOVAL AND INSTALLATION ...............13
RADIATOR ....................................... .................13
Exploded View ..................................................... ....13
Removal and Installation .........................................13
Inspection ................................................................15
COOLING FAN ..................................................16
Exploded View .........................................................16
Removal and Installation .........................................16
Inspection ................................................................17
WATER PUMP ..................................................18
Exploded View .........................................................18
Removal and Installation .........................................18
Inspection ................................................................19
WATER INLET AND THERMOSTAT ASSEM-
BLY ....................................................................
20
Exploded View .........................................................20
Removal and Installation .........................................20
Inspection ................................................................21
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .............................................
23
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
23
Periodical Maintenance Specification ................ ....23
Radiator ...................................................................23
Thermostat ..............................................................23
Revision: 2010 May2011 QX56

CO-6
< SYMPTOM DIAGNOSIS >
OVERHEATING CAUSE ANALYSIS
SYMPTOM DIAGNOSIS
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000006289656
Symptom Check items
Cooling sys-
tem parts
malfunction Poor heat transfer
Water pump malfunction Worn or loose drive belt
—
Thermostat stuck closed —
Damaged fins
Dust contamination or pa-
per clogging
Physical damage
Clogged radiator cooling
tube Excess foreign material
(rust, dirt, sand, etc.)
Reduced air flow Cooling fan does not oper-
ate
Fan assembly —
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio ———
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolant Engine coolant leakageCooling hose
Loose clamp
Cracked hose
Water pump Poor sealing
Radiator cap Loose
Poor sealing
Radiator O-ring for da
mage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tank Exhaust gas leakage into
cooling system Cylinder head deterioration
Cylinder head gasket deteri-
oration
Revision: 2010 May2011 QX56

OVERHEATING CAUSE ANALYSISCO-7
< SYMPTOM DIAGNOSIS >
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Except cool-
ing system
parts mal-
function — Overload on engine
Abusive driving
High engine rpm under no
load
Driving in low gear for ex-
tended time
Driving at extremely high
speed
Powertrain system malfunc-
tion
—
Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flow Blocked bumper —
—
Blocked radiator grille
Installed car brassiere
Mud contamination or paper
clogging
Blocked radiator —
Blocked condenser Blocked air flow
Installed large fog lamp
Symptom Check items
Revision: 2010 May2011 QX56

CO-10
< PERIODIC MAINTENANCE >
ENGINE COOLANT
Watch water temperature gauge so as not to overheat engine.
9. Stop the engine and cool down to less than approximately 50 °C (122 °F).
 Cool down using fan to reduce the time.
 If necessary, refill radiator up to filler neck with engine coolant.
10. Refill reservoir tank to “MAX” level line with engine coolant if necessary.
11. Repeat steps 6 through 10 two or more times with reservoir tank cap installed until engine coolant level no longer drops.
12. Check cooling system for leakage with engine running.
13. Warm up the engine, and check for sound of engine coolant flow while running engine from idle up to 3,000 rpm with heater temperature controller set at several position between “COOL” and “WARM”.
 Sound may be noticeable at heater unit.
14. Repeat step 13 three times.
15. If sound is heard, bleed air from cooling system by repeating step 4, and steps from 6 to 14 until engine
coolant level no longer drops.
FlushingINFOID:0000000006289660
1. Install reservoir tank if removed, and radiator drain plug. CAUTION:
Be sure to clean drain plug and install with new O-ring. Refer to CO-13, "
Exploded View".
If water drain plug on cylinder block is removed, close and tighten it. Refer to EM-107, "
Disassem-
bly and Assembly".
2. Remove air relief plug (1) on heater hose.
3. Fill radiator and reservoir tank with water until water spills from the air relief holes, then close air relief
plugs with clamp. Fill radiator and reservoir tank with water and reinstall caps.
4. Run the engine and warm it up to normal operating temperature.
5. Rev the engine two or three times under no-load.
6. Stop the engine and wait until it cools down.
7. Drain water from the system. Refer to CO-8, "
Draining".
8. Repeat steps 1 through 7 until clear water begins to drain from radiator. : 1.96 N·m (0.2 kg-m, 17 in-lb)
2. Engine cover
: Vehicle front
JPBIA3429ZZ
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (ECM)EC-71
< SYSTEM DESCRIPTION > [VK56VD]
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*: Leaving cooling fan OFF with CONSULT-III while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For items whose SRT codes are set, “CMPLT” is disp
layed on the CONSULT-III screen; for items whose SRT
codes are not set, “INCMP” is displayed.
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1456 does not apply but appears in DTC Work Support Mode screens. V/T ASSIGN AN-
GLE
 Engine: Return to the original
non-standard condition
 Change intake valve timing using CONSULT-III. If malfunctioning symptom disap-
pears, see CHECK ITEM.
 Harness and connectors
 Intake valve timing control sole-
noid valve
FPCM  Engine: Return to the original
trouble condition
 Select “LOW”, “MID” and “HI” with CONSULT-III. Fuel pump speed changes or stops.
 Harness and connectors
 Fuel pump control module (FPCM)
TEST ITEM CONDITION JUDGMENT CHECK ITEM (REMEDY)
Test mode Test item Corresponding DTC No. Reference page
HO2S2 HO2S2 (B1) P1146 P0138
EC-249
HO2S2 (B1) P1147 P0137EC-243
HO2S2 (B1) P0139 P0139EC-257
HO2S2 (B2) P1166 P0158EC-249
HO2S2 (B2) P1167 P0157EC-243
HO2S2 (B2) P0159 P0159EC-257
A/F SEN1A/F SEN1 (B1) P1278/P1279 P0133
EC-238A/F SEN1 (B1) P1276 P0130EC-228
A/F SEN1 (B2) P1288/P1289 P0153EC-238
A/F SEN1 (B2) P1286 P0150EC-228
EVAPORATIVE SYSTEMEVP V/S LEAK P0456/P1456* P0456
EC-346, "
DTC Logic"
PURG VOL CN/V P1444 P0443EC-317, "DTC Logic"
PURG FLOW P0441 P0441EC-312, "DTC Logic"
Revision: 2010 May2011 QX56

EC-98
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
NOTE:
*: If “P1197” is displayed with other DTC in priority 1, perform trouble diagnosis for “P1197” first.
DTC IndexINFOID:0000000006217733
×
:Applicable —: Not applicable
2  P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater
 P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
 P0075 P0081 Intake valve timing control solenoid valve
 P0130 P0131 P0132 P0133 P0150 P0151 P0152 P015 3 P2A00 P2A03 Air fuel ratio (A/F) sensor 1
 P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2
 P0190 - P0193 FRP sensor
 P0441 EVAP control system purge flow monitoring
 P0443 P0444 P0445 EVAP canister purge volume control solenoid valve
 P0447 P0448 EVAP canister vent control valve
 P0451 P0452 P0453 EVAP control system pressure sensor
 P0550 Power steering pressure sensor
 P0603 ECM power supply
 P0710 P0717 P0720 P0729 P0730 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P0750 P0775 P0780 P0795 P1730 P1734 P2713 P2722 P2731 P2807 A/T related sensors, solenoid valves and switches
 P1087 P1088 VVEL system
 P1090 P1093 VVEL actuator motor
 P1091 VVEL actuat or motor relay
 P1217 Engine over temperature (OVERHEAT)
 P1650 Starter motor relay 2
 P1651 Starter motor relay
 P2101 Electric throttle control function
 P2118 Throttle control motor
 P1805 Brake switch
 P2100 P2103 Throttle control motor relay
 P2101 Electric throttle control function
3  P0011 P0021 Intake valve timing control  P0087, P0088, P0090 FRP control system
 P008A Low fuel pressure control system
 P008B Low fuel pressure control system
 P0171 P0172 P0174 P0175 Fuel injection system function
 P0201 - P0208 Injector
 P0300 - P0308 Misfire
 P0420 P0430 Three way catalyst function
 P0456 EVAP control system (VERY SMALL LEAK)
 P0506 P0507 Idle speed control system
 P050E Cold start control
 P0524 Engine oil pressure
 P1148 P1168 Closed loop control
 P1212 TCS communication line
 P1421 Cold start control
 P1564 ASCD steering switch / ICC steering switch
 P1652 Starter motor system communication
 P2119 Electric throttle control actuator
 P1564 ASCD steering switch / ICC steering switch
 P1568 ICC command value
 P1572 ASCD brake switch / ICC brake switch
 P1574 ASCD vehicle speed sensor / ICC vehicle speed sensor
Priority Detected items (DTC)
DTC*1
Items
(CONSULT-III screen terms) SRT code Trip MIL
Reference
page
CONSULT-III
GST*
2ECM*3
U0101 0101 LOST COMM (TCM) — 1 ×EC-171
U0113 0113 CAN COMM CIRCUIT — 1 ×EC-173
U1001
1001*4CAN COMM CIRCUIT — 1 or 2 — EC-172
U1003 1003 CAN COMM CIRCUIT — 2 — EC-173
Revision: 2010 May2011 QX56

EC-222
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0125 ECT SENSOR
P0125 ECT SENSOR
DTC LogicINFOID:0000000006288280
DTC DETECTION LOGIC
NOTE:
If DTC P0125 is displayed with P0117 or P0118,
first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-217, "
DTC 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.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
WITH GST
Follow the procedure “With CONSULT-III” above.
Is the temperature above 10
°C (50°F)?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Start engine and run it for 65 minutes at idle speed. If “COOLAN TEMP/S” increases to more than 10 °C (50 °F) within 65 minutes, stop engine because
the test result will be OK.
CAUTION:
Never overheat engine.
2. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> EC-222, "Diagnosis Procedure"
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288281
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-218, "
Component Inspection (Engine Coolant Temperature Sensor)".
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0125 ECT SENSOR
(Insufficient engine coolant
temperature for closed loop
fuel control)  Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
 Engine coolant temperature is insufficient for closed loop fuel control.  Harness or connectors
(High resistance in the circuit)
 Engine coolant temperature sensor
 Thermostat
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