2009 INFINITI QX56 overheating

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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
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
2
Precaution for Liquid Gasket .....................................3
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tool ........................................... ......4
Commercial Service Tool ..........................................5
FUNCTION DIAGNOSIS ...............................6
COOLING SYSTEM ....................................... .....6
Cooling Circuit ..................................................... ......6
Schematic .................................................................7
OVERHEATING CAUSE ANALYSIS ..................8
Troubleshooting Chart ...............................................8
ON-VEHICLE MAINTENA NCE ....................10
ENGINE COOLANT ....................................... ....10
Inspection ............................................................ ....10
Changing Engine Coolant .......................................11
RADIATOR ........................................................14
Checking Radiator ............................................... ....14
ON-VEHICLE REPAIR .................................15
RADIATOR ....... .................................................15
Exploded View ..................................................... ....15
Removal and Installation .........................................15
ENGINE COOLING FAN ...................................18
Exploded View .........................................................18
Removal and Installation (Crankshaft Driven
Type) .......................................................................
18
Removal and Installation (Motor Driven Type) ........19
WATER PUMP ..................................................20
Exploded View .........................................................20
Removal and Installation .........................................20
THERMOSTAT AND WATER PIPING ..............22
Exploded View .........................................................22
Removal and Installation .........................................22
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
24
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
24
Standard and Limit .............................................. ....24
Revision: December 20092009 QX56

CO-8
< FUNCTION DIAGNOSIS >
OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000003771283
SymptomCheck items
Cooling sys-
tem parts
malfunction Poor heat transfer
Water pump malfunction Worn or loose drive belt
—
Thermostat stuck closed Coolant circulation
Damaged fins
Dust contamination or pa-
per clogging
Physical damage
Clogged radiator cooling
tube Excess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunction Excess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flow Cooling fan does not oper-
ate
Fan assembly —
High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud —Radiator shroud —
Improper engine coolant
mixture ratio —
Engine coolant viscosity —
Poor engine coolant quality —Engine coolant density —
Insufficient engine coolant Engine coolant leaksCooling 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 leaks into cool-
ing system Cylinder head deterioration
Cylinder head gasket deteri-
oration
Revision: December 20092009 QX56

OVERHEATING CAUSE ANALYSISCO-9
< FUNCTION 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 radiator grille Installed car brassiere
—
Mud contamination or paper
clogging
Blocked bumper
Blocked radiator
Blocked condenser
Blocked air flow
Installed large fog lamp
Symptom
Check items
Revision: December 20092009 QX56

EC-5
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EC A
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On Board Diagnosis Logic ..................................
..
295
P1211 TCS CONTROL UNIT ...........................296
Description .......................................................... ..296
On Board Diagnosis Logic ....................................296
DTC Confirmation Procedure ................................296
Diagnosis Procedure .............................................296
P1212 TCS COMMUNICATION LINE ..............297
Description .......................................................... ..297
On Board Diagnosis Logic ....................................297
DTC Confirmation Procedure ................................297
Diagnosis Procedure .............................................297
P1217 ENGINE OVER TEMPERATURE .........298
On Board Diagnosis Logic .................................. ..298
Overall Function Check .........................................298
Diagnosis Procedure .............................................299
Main 13 Causes of Overheating ............................300
P1225 TP SENSOR ..........................................302
Component Description ....................................... ..302
On Board Diagnosis Logic ....................................302
DTC Confirmation Procedure ................................302
Diagnosis Procedure .............................................302
P1226 TP SENSOR ..........................................304
Component Description ....................................... ..304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ................................304
Diagnosis Procedure .............................................304
P1421 COLD START CONTROL .....................306
Description .......................................................... ..306
On Board Diagnosis Logic ....................................306
DTC Confirmation Procedure ................................306
Diagnosis Procedure .............................................306
P1550 BATTERY CURRENT SENSOR ...........308
Component Description ....................................... ..308
On Board Diagnosis Logic ....................................308
DTC Confirmation Procedure ................................308
Diagnosis Procedure .............................................308
Component Inspection ..........................................310
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
Component Inspection ..........................................314
P1553 BATTERY CURRENT SENSOR ...........316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1554 BATTERY CURRENT SENSOR ...........320
Component Description ....................................... ..320
On Board Diagnosis Logic .....................................320
Overall Function Check .........................................320
Diagnosis Procedure .............................................321
Component Inspection ...........................................322
P1564 ICC STEERING SWITCH .....................324
Component Description .........................................324
On Board Diagnosis Logic .....................................324
DTC Confirmation Procedure ................................324
Diagnosis Procedure .............................................324
Component Inspection ...........................................326
P1564 ASCD STEERING SWITCH .................328
Component Description .........................................328
On Board Diagnosis Logic .....................................328
DTC Confirmation Procedure ................................328
Diagnosis Procedure .............................................328
Component Inspection ...........................................330
P1568 ICC FUNCTION ....................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
P1572 ICC BRAKE SWITCH ..........................333
Component Description .........................................333
On Board Diagnosis Logic .....................................333
DTC Confirmation Procedure ................................333
Diagnosis Procedure .............................................334
Component Inspection ...........................................337
P1572 ASCD BRAKE SWITCH ......................339
Component Description .........................................339
On Board Diagnosis Logic .....................................339
DTC Confirmation Procedure ................................339
Diagnosis Procedure .............................................340
Component Inspection ...........................................343
P1574 ICC VEHICLE SPEED SENSOR .........344
Component Description .........................................344
On Board Diagnosis Logic .....................................344
DTC Confirmation Procedure ................................344
Diagnosis Procedure .............................................344
P1574 ASCD VEHICLE SPEED SENSOR .....346
Component Description .........................................346
On Board Diagnosis Logic .....................................346
DTC Confirmation Procedure ................................346
Diagnosis Procedure .............................................346
P1805 BRAKE SWITCH .................................348
Description .............................................................348
On Board Diagnosis Logic .....................................348
DTC Confirmation Procedure ................................348
Diagnosis Procedure .............................................348
Component Inspection ...........................................350
P2100, P2103 THROTTLE CONTROL MO-
TOR RELAY ....................................................
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Component Description .........................................351
Revision: December 20092009 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-189
< COMPONENT DIAGNOSIS > [VK56DE]
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P0300, P0301, P0302, P0303, P0304,
P0305, P0306, P0307, P0308 MIS-
FIRE
On Board Diagnosis LogicINFOID:0000000003771454
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary , ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage) On the 1st trip, when a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level t hat will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration) For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a second trip. Du ring this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC Confirmation ProcedureINFOID:0000000003771455
CAUTION:
Always drive vehicle in safe manner according to traf fic conditions and obey all traffic laws when driv-
ing.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300 Multiple cylinder misfire
detected
Multiple cylinder misfire.
 Improper spark plug
 Insufficient compression
 Incorrect fuel pressure
 The injector circuit is open or shorted
 Fuel injector
 Intake air leak
 The ignition signal circuit is open or short-ed
 Lack of fuel
 Signal plate
 Air fuel ratio (A/F) sensor 1
 Incorrect PCV hose connection
P0301
0301
No.1 cylinder misfire de-
tected
No. 1 cylinder misfires.
P0302
0302 No. 2 cylinder misfire
detected
No. 2 cylinder misfires.
P0303
0303 No. 3 cylinder misfire
detected
No. 3 cylinder misfires.
P0304
0304 No. 4 cylinder misfire
detected
No. 4 cylinder misfires.
P0305
0305 No. 5 cylinder misfire
detected
No. 5 cylinder misfires.
P0306
0306 No. 6 cylinder misfire
detected
No. 6 cylinder misfires.
P0307
0307 No. 7 cylinder misfire
detected
No. 7 cylinder misfires.
P0308
0308 No. 8 cylinder misfire
detected
No. 8 cylinder misfires.
Revision: December 20092009 QX56

EC-298
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
P1217 ENGINE OVER TEMPERATURE
On Board Diagn
osis LogicINFOID:0000000003771589
NOTE:
If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-86
.
 If DTC P1217 is displayed with DTC P0607, first pe rform the trouble diagnosis for DTC P0607. Refer
to EC-284
.
If the cooling fan or another component in the coo ling 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 su re 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:0000000003771590
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-388,
"Diagnosis Procedure".
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-388,
"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 diven)
 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-300,
"Main 13 Causes of Overheating".
SEF621W
Revision: December 20092009 QX56

EC-300
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
4. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to "PROCEDURE
A".)
4.CHECK COOLING SYSTEM FOR LEAK
Refer to CO-10, "Inspection"
.
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. Hose
 Radiator
 Radiator cap
 Water pump
 Reservoir tank
5.CHECK COMPONENT PARTS
Check the following.
 RESERVOIR TANK CAP (Refer to CO-10, "Inspection"
.)
 Thermostat. (Refer to CO-22, "Removal and Installation"
.)
 Engine coolant temperature sensor. (Refer to EC-122, "Component Inspection"
.)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
6.CHECK MAIN 13 CAUSES
If the cause cannot be isolated, go to EC-300, "Main 13 Causes of Overheating"
.
>> INSPECTION END
Main 13 Causes of OverheatingINFOID:0000000003771592
SEF882V
Engine Step Inspection item Equipment Standard Reference page
OFF 1  Blocked radiator  Blocked condenser
 Blocked radiator grille
 Blocked bumper  Visual No blocking —
2  Coolant mixture  Coolant tester 50 - 50% coolant mixture CO-10
3  Coolant level  Visual Coolant up to MAX level in
reservoir tank and radiator
filler neckCO-11, "Changing Engine
Coolant"
4  Reservoir tank cap  Pre
ssure tester 95 - 125 kPa
(0.97 - 1.28 kg/cm2, 14 -
18 psi) (Limit) CO-10, "Inspection"
ON*25  Coolant leaks  Visual No leaks
CO-10, "Inspection"
ON*26  Thermostat  Touch the upper and
lower radiator hosesBoth hoses should be hot
CO-22, "Removal and In-
stallation"
ON*17  Cooling fan  CONSULT-III Operating See trouble diagnosis for
DTC P1217 (EC-36
).
Revision: December 20092009 QX56