2008 INFINITI QX56 engine overheat

CCS
DTC109 LASER HIGH TEMPCCS-45
< COMPONENT DIAGNOSIS >
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DTC109 LASER HIGH TEMP
DTC 109 LASER HIGH TEMPINFOID:0000000001744720
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 adjust laser beam aiming. Refer to CCS-71, "
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: March 2010 2008 QX56

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
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
Removal and Installation ..................................... ....15
ENGINE COOLING FAN ...................................18
Removal and Installation (Crankshaft Driven
Type) .......................................................................
18
Removal and Installation (Motor Driven Type) ........19
WATER PUMP ..................................................20
Removal and Installation .........................................20
THERMOSTAT AND WATER PIPING ..............22
Removal and Installation .........................................22
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .......................................... ...
24
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
24
Standard and Limit .............................................. ....24
Revision: March 2010 2008 QX56

CO-8
< FUNCTION DIAGNOSIS >
OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
Troubleshooting ChartINFOID:0000000001538857
SymptomCheck 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.)
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 —— —
Improper engine coolant
mixture ratio ———
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: March 2010
2008 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 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: March 2010 2008 QX56

EC-5
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EC A
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P1148, P1168 CLOSED LOOP CONTROL ... ..303
On Board Diagnosis Logic .................................. ..303
P1211 TCS CONTROL UNIT ...........................304
Description .......................................................... ..304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ................................304
Diagnosis Procedure .............................................304
P1212 TCS COMMUNICATION LINE ..............305
Description .......................................................... ..305
On Board Diagnosis Logic ....................................305
DTC Confirmation Procedure ................................305
Diagnosis Procedure .............................................305
P1217 ENGINE OVER TEMPERATURE .........306
On Board Diagnosis Logic .................................. ..306
Overall Function Check .........................................306
Diagnosis Procedure .............................................307
Main 13 Causes of Overheating ............................308
P1225 TP SENSOR ..........................................310
Component Description ....................................... ..310
On Board Diagnosis Logic ....................................310
DTC Confirmation Procedure ................................310
Diagnosis Procedure .............................................310
P1226 TP SENSOR ..........................................312
Component Description ....................................... ..312
On Board Diagnosis Logic ....................................312
DTC Confirmation Procedure ................................312
Diagnosis Procedure .............................................312
P1421 COLD START CONTROL .....................314
Description .......................................................... ..314
On Board Diagnosis Logic ....................................314
DTC Confirmation Procedure ................................314
Diagnosis Procedure .............................................314
P1550 BATTERY CURRENT SENSOR ...........316
Component Description ....................................... ..316
On Board Diagnosis Logic ....................................316
DTC Confirmation Procedure ................................316
Diagnosis Procedure .............................................316
Component Inspection ..........................................318
P1551, P1552 BATTERY CURRENT SEN-
SOR ..................................................................
320
Component Description ....................................... ..320
On Board Diagnosis Logic ....................................320
DTC Confirmation Procedure ................................320
Diagnosis Procedure .............................................320
Component Inspection ..........................................322
P1553 BATTERY CURRENT SENSOR ...........324
Component Description ....................................... ..324
On Board Diagnosis Logic ....................................324
DTC Confirmation Procedure ................................324
Diagnosis Procedure .............................................324
Component Inspection ..........................................326
P1554 BATTERY CURRENT SENSOR ..........328
Component Description ....................................... ..328
On Board Diagnosis Logic .....................................328
Overall Function Check .........................................328
Diagnosis Procedure .............................................329
Component Inspection ...........................................330
P1564 ICC STEERING SWITCH .....................332
Component Description .........................................332
On Board Diagnosis Logic .....................................332
DTC Confirmation Procedure ................................332
Diagnosis Procedure .............................................332
Component Inspection ...........................................335
P1564 ASCD STEERING SWITCH .................336
Component Description .........................................336
On Board Diagnosis Logic .....................................336
DTC Confirmation Procedure ................................336
Diagnosis Procedure .............................................336
Component Inspection ...........................................338
P1568 ICC FUNCTION ....................................340
On Board Diagnosis Logic .....................................340
DTC Confirmation Procedure ................................340
Diagnosis Procedure .............................................340
P1572 ICC BRAKE SWITCH ..........................341
Component Description .........................................341
On Board Diagnosis Logic .....................................341
DTC Confirmation Procedure ................................341
Diagnosis Procedure .............................................342
Component Inspection ...........................................346
P1572 ASCD BRAKE SWITCH ......................347
Component Description .........................................347
On Board Diagnosis Logic .....................................347
DTC Confirmation Procedure ................................347
Diagnosis Procedure .............................................348
Component Inspection ...........................................351
P1574 ICC VEHICLE SPEED SENSOR .........352
Component Description .........................................352
On Board Diagnosis Logic .....................................352
DTC Confirmation Procedure ................................352
Diagnosis Procedure .............................................352
P1574 ASCD VEHICLE SPEED SENSOR .....354
Component Description .........................................354
On Board Diagnosis Logic .....................................354
DTC Confirmation Procedure ................................354
Diagnosis Procedure .............................................354
P1805 BRAKE SWITCH .................................356
Description .............................................................356
On Board Diagnosis Logic .....................................356
DTC Confirmation Procedure ................................356
Diagnosis Procedure .............................................356
Component Inspection ...........................................358
P2100, P2103 THROTTLE CONTROL MO-
TOR RELAY ....................................................
359
Revision: March 2010 2008 QX56

EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: 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-462, "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
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) FunctionINFOID:0000000001351349
DESCRIPTION
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 •Engine: Idle
• Change duty ratio using CON-
SULT-III. Battery voltage changes. • Harness and connectors
• IPDM E/R
•Alternator
TEST ITEM
CONDITION JUDGEMENTCHECK ITEM (REMEDY)
Test mode Test itemCorresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441
P0441EC-219
EVP SML LEAK P0442/P1442* P0442
EC-224P0455EC-259
EVP V/S LEAK P0456/P1456* P0456EC-266
PURG VOL CN/V P1444 P0443EC-231
A/F SEN1 A/F SEN1 (B1) P1276
P0130EC-141A/F SEN1 (B1) P1278/P1279 P0133EC-153
A/F SEN1 (B2) P1286 P0150EC-141
A/F SEN1 (B2) P1288/P1289 P0153EC-153
HO2S2 HO2S2 (B1) P0139
P0139EC-171
HO2S2 (B1) P1146 P0138EC-164
HO2S2 (B1) P1147 P0137EC-159
HO2S2 (B2) P0159 P0159EC-171
HO2S2 (B2) P1166 P0158EC-164
HO2S2 (B2) P1167 P0157EC-159
Revision: March 2010 2008 QX56

EC-132
< COMPONENT DIAGNOSIS >[VK56DE]
P0125 ECT SENSOR
P0125 ECT SENSOR
Component DescriptionINFOID:0000000001351440
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 elec trical 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 when measuring input/output voltage. Doi ng 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:0000000001351441
DTC Confirmation ProcedureINFOID:0000000001351442
CAUTION:
Be careful not to overheat engine.
NOTE:
•If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117,
P0118. Refer to EC-125, "
DTC Confirmation Procedure".
• If DTC P0125 is displayed with P0116, first perf orm the trouble diagnosis for DTC P011. Refer to EC-
121, "DTC Confirmation Procedure".
• If DTC confirmation procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 31 °C (88° F).
If it is above 31° C (88°F), the test result will be OK.
If it is below 31 °C (88° F), go to following step.
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: March 2010 2008 QX56

EC-306
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
P1217 ENGINE OVER TEMPERATURE
On Board Diagn
osis LogicINFOID:0000000001351714
NOTE:
•If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-87
.
• If DTC P1217 is displayed with DTC U1010, first pe rform the trouble diagnosis for DTC U1010. Refer
to EC-88
.
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:0000000001351715
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-395,
"Diagnosis Procedure".
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-395,
"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-308,
"Main 13 Causes of Overheating".
SEF621W
Revision: March 2010 2008 QX56