2010 INFINITI QX56 engine overheat

CCS-46
< COMPONENT DIAGNOSIS >
DTC109 LASER HIGH TEMP
DTC109 LASER HIGH TEMP
DTC 109 LASER HIGH TEMPINFOID:0000000005146003
1.CHECK SYMPTOM
Inspect engine cooling system.
Did the engine overheat?
YES >> • Repair cooling system. • Erase DTC and perform ICC system running test. Refer to CCS-8, "
ACTION TEST : ICC Sys-
tem Running Test". Then perform self-diagnosis of ICC system again.
NO >> • Replace ICC sensor and adjus t laser beam aiming. Refer to CCS-72, "
ICC Sensor".
• Erase DTC, then perform ICC system running test. Refer to CCS-8, "
ACTION TEST : ICC Sys-
tem Running Test". Then perform self-diagnosis of ICC system again.
Revision: April 20092010 QX56

CO-1
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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 ..........................................4
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: April 20092010 QX56

CO-8
< FUNCTION DIAGNOSIS >
OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000005149040
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 —
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: April 20092010 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: April 20092010 QX56

EC-5
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EC A
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P1140, P1145 IVT CONTROL POSITION
SENSOR ......................................................... ..
295
Component Description ....................................... ..295
On Board Diagnosis Logic ....................................295
DTC Confirmation Procedure ................................295
Diagnosis Procedure .............................................295
Component Inspection ..........................................298
P1148, P1168 CLOSED LOOP CONTROL .....299
On Board Diagnosis Logic .................................. ..299
P1211 TCS CONTROL UNIT ...........................300
Description .......................................................... ..300
On Board Diagnosis Logic ....................................300
DTC Confirmation Procedure ................................300
Diagnosis Procedure .............................................300
P1212 TCS COMMUNICATION LINE ..............301
Description .......................................................... ..301
On Board Diagnosis Logic ....................................301
DTC Confirmation Procedure ................................301
Diagnosis Procedure .............................................301
P1217 ENGINE OVER TEMPERATURE .........302
On Board Diagnosis Logic .................................. ..302
Overall Function Check .........................................302
Diagnosis Procedure .............................................303
Main 13 Causes of Overheating ............................304
P1225 TP SENSOR ..........................................306
Component Description ....................................... ..306
On Board Diagnosis Logic ....................................306
DTC Confirmation Procedure ................................306
Diagnosis Procedure .............................................306
P1226 TP SENSOR ..........................................308
Component Description ....................................... ..308
On Board Diagnosis Logic ....................................308
DTC Confirmation Procedure ................................308
Diagnosis Procedure .............................................308
P1421 COLD START CONTROL .....................310
Description .......................................................... ..310
On Board Diagnosis Logic ....................................310
DTC Confirmation Procedure ................................310
Diagnosis Procedure .............................................310
P1550 BATTERY CURRENT SENSOR ...........312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
Component Inspection ..........................................314
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1553 BATTERY CURRENT SENSOR ..........320
Component Description ....................................... ..320
On Board Diagnosis Logic .....................................320
DTC Confirmation Procedure ................................320
Diagnosis Procedure .............................................320
Component Inspection ...........................................322
P1554 BATTERY CURRENT SENSOR ..........324
Component Description .........................................324
On Board Diagnosis Logic .....................................324
Overall Function Check .........................................324
Diagnosis Procedure .............................................325
Component Inspection ...........................................326
P1564 ICC STEERING SWITCH .....................328
Component Description .........................................328
On Board Diagnosis Logic .....................................328
DTC Confirmation Procedure ................................328
Diagnosis Procedure .............................................328
Component Inspection ...........................................330
P1564 ASCD STEERING SWITCH .................332
Component Description .........................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
Component Inspection ...........................................334
P1568 ICC FUNCTION ....................................336
On Board Diagnosis Logic .....................................336
DTC Confirmation Procedure ................................336
Diagnosis Procedure .............................................336
P1572 ICC BRAKE SWITCH ..........................337
Component Description .........................................337
On Board Diagnosis Logic .....................................337
DTC Confirmation Procedure ................................337
Diagnosis Procedure .............................................338
Component Inspection ...........................................343
P1572 ASCD BRAKE SWITCH ......................344
Component Description .........................................344
On Board Diagnosis Logic .....................................344
DTC Confirmation Procedure ................................344
Diagnosis Procedure .............................................345
Component Inspection ...........................................348
P1574 ICC VEHICLE SPEED SENSOR .........349
Component Description .........................................349
On Board Diagnosis Logic .....................................349
DTC Confirmation Procedure ................................349
Diagnosis Procedure .............................................349
P1574 ASCD VEHICLE SPEED SENSOR .....351
Component Description .........................................351
On Board Diagnosis Logic .....................................351
DTC Confirmation Procedure ................................351
Diagnosis Procedure .............................................351
P1805 BRAKE SWITCH .................................353
Description .............................................................353
Revision: April 20092010 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-71
< FUNCTION DIAGNOSIS > [VK56DE]
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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 details, refer to
EC-459, "DTC Index".
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
TEST ITEM CONDITION JUDGEMENTCHECK ITEM (REMEDY)
FUEL INJEC-
TION • Engine: Return to the original
trouble condition
• Change the amount of fuel injec-
tion using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Harness and connectors
• Fuel injector
• Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING • Engine: Return to the original
trouble condition
• Timing light: Set
• Retard the ignition timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Perform Idle Air Volume Learning.
POWER BAL-
ANCE • Engine: After warming up, idle the
engine.
• A/C switch: OFF
• Selector lever: P or N
• Cut off each injector signal one at a time using CONSULT-III. Engine runs rough or dies.
• Harness and connectors
• Compression
• Fuel injector
• Power transistor
•Spark plug
• Ignition coil
COOLING FAN* • Ignition switch: ON
• Turn the cooling fan HI and OFF
using CONSULT-III. Cooling fan moves and stops. • Harness and connectors
• Cooling fan motor
•IPDM E/R
ENG COOLANT
TEMP • Engine: Return to the original
trouble condition
• Change the engine coolant tem- perature using CONSULT-III. If trouble symptom disappears, see
CHECK ITEM. • Harness and connectors
• Engine coolant temperature sen-
sor
• Fuel injector
FUEL PUMP RE-
LAY • Ignition switch: ON
(Engine stopped)
• Turn the fuel pump relay ON and OFF using CONSULT-III and lis-
ten to operating sound. Fuel pump relay makes the operat-
ing sound.
• Harness and connectors
• Fuel pump relay
PURG VOL
CONT/V • Engine: After warming up, run en-
gine at 1,500 rpm.
• Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-III. Engine speed changes according to
the opening percent.
• Harness and connectors
• Solenoid valve
FUEL/T TEMP
SEN • Change the fuel tank temperature using CONSULT-III.
VENT CON-
TROL/V • Ignition switch: ON
(Engine stopped)
• Turn solenoid valve ON and OFF with the CONSULT-III and listen
to operating sound. Solenoid valve makes an operating
sound.
• Harness and connectors
• Solenoid valve
V/T ASSIGN AN-
GLE • Engine: Return to the original
trouble condition
• Change intake valve timing using
CONSULT-III. If trouble symptom disappears, see
CHECK ITEM.
• Harness and connectors
• Intake valve timing control sole-
noid valve
ALTERNATOR
DUTY •
E
ngine: Idle
• Change duty ratio using CON- SULT-III. Battery voltage changes. • Harness and connectors
•IPDM E/R
• Alternator
Revision: April 20092010 QX56

P0125 ECT SENSOREC-129
< COMPONENT DIAGNOSIS > [VK56DE]
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P0125 ECT SENSOR
Component DescriptionINFOID:0000000005149141
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor
modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000005149142
NOTE:
•If DTC P0125 is displayed with P0 116, first perform the trouble diagnosis for DTC P0116. Refer to EC-
129, "DTC Confirmation Procedure".
• If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-122, "
DTC Confirmation Procedure".
DTC Confirmation ProcedureINFOID:0000000005149143
CAUTION:
Be careful not to overheat engine.
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
SEF594K
Engine coolant temperature °C ( °F)] Voltage* (V)
Resistance (kΩ)
–10 (14) 4.47.0 - 11.4
20 (68) 3.52.1 - 2.9
50 (122) 2.20.68 - 1.00
90 (194) 0.90.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0125
0125 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: April 20092010 QX56

EC-192
< COMPONENT DIAGNOSIS >[VK56DE]
P0300, P0301, P0302, P
0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MIS-
FIRE
On Board Diagn osis LogicINFOID:0000000005149211
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 that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can dam age the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level that 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:0000000005149212
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws when driv-
ing.
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speedOn 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: April 20092010 QX56