2004 INFINITI QX56 radiator

TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
1 - 6: The numbers refer to the order of inspection.Cooling Radiator/Hose/Radiator filler cap
55555 55 45CO-10
Thermostat 5CO-17
Water pum pCO-15
Water galleryCO-6
Cooling fan
5EC-410
Coolant level (Low)/Contami-
nated coolantCO-8
IVIS (Infinti Vehicle Immobilizer System —
NATS)11EC-63 or
BL-138
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA

EC-180Revision: August 2007
DTC P0125 ECT SENSOR
2004 QX56
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70°C (158°F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-17, "
THERMOSTAT AND WATER PIPING" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H22
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

*: This data is reference value and is measured between ECM terminal 73
(Engine coolant temperature sensor) and ground.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationUBS00H23
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-17, "THERMOSTAT AND WATER PIPING" .
PBIB2064E
Engine coolant
temperature°C (°F)Voltage* V Resistance kΩ
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF 0 12 P

DTC P1217 ENGINE OVER TEMPERATURE
EC-411
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Revision: August 20072004 QX56
On Board Diagnosis LogicUBS00H8V
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally 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-8, "
Changing Engine
Coolant" . Also, replace the engine oil. Refer to LU-8, "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 MA-11, "
ANTI-FREEZE COOLANT MIXTURE
RATIO" .
2. After refilling coolant, run engine to ensure that no water-flow noise is emitted.
Overall Function CheckUBS00H8W
Use this procedure to check the overall function of the cooling fan. During this check, a DTC might not be con-
firmed.
WA RN ING:
Never remove the radiator cap when the engine is hot. Serious burns could be caused by high pres-
sure 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.
WITH CONSULT-II
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-415,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-415,
"Diagnostic Procedure" .
3. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1217
1217Engine over tempera-
ture (Overheat)

Cooling fan does not operate properly (Over-
heat).

Cooling fan system does not operate prop-
erly (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
shorted.)

Cooling fan

Radiator hose

Radiator

Radiator cap

Water pump

Thermostat
For more information, refer to EC-418,
"Main 12 Causes of Overheating" .
SEF 6 21 W

EC-412Revision: August 2007
DTC P1217 ENGINE OVER TEMPERATURE
2004 QX56
4. Perform “COOLING FAN” in “ACTIVE TEST” mode with CON-
SULT-II.
5. If the results are NG, go to EC-415, "
Diagnostic Procedure" .
WITH GST
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-415,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-415,
"Diagnostic Procedure" .
3. Disconnect engine coolant temperature sensor harness connec-
tor.
4. Connect 150Ω resistor to engine coolant temperature sensor
harness connector.
5. Start engine and make sure that cooling fan operates at higher
speed than low speed.
Be careful not to overheat engine.
6. If NG, go to EC-415, "
Diagnostic Procedure" .
SEF 6 46 X
SEF 6 21 W
SEF 8 82 V

EC-416Revision: August 2007
DTC P1217 ENGINE OVER TEMPERATURE
2004 QX56
4. CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the
pressure drops.
CAUTION:
Higher than the specified pressure may cause radiator damage.
Pressure should not drop.
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. Refer to CO-8, "
CHECK-
ING COOLING SYSTEM FOR LEAKS" .

Hose

Radiator

Wate r p ump
5. CHECK RADIATOR CAP
Apply pressure to cap with a tester.
OK or NG
OK >> GO TO 6.
NG >> Replace radiator cap.
6. CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
3. Check if valve is closed at 5°C (9°F) below valve opening tem-
perature.
For details, refer to CO-17, "
THERMOSTAT AND WATER PIP-
ING" .
OK or NG
OK >> GO TO 7.
NG >> Replace thermostat
7. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-169, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace engine coolant temperature sensor.Testing pressure: 157 kPa (1.6 kg/cm
2 , 23 psi)
PBIC1528E
Radiator cap relief
pressure:59 - 98 kPa (0.6 - 1.0 kg/cm2
, 9 - 14 psi)
SL C7 55 A
Valve opening temperature: 82°C (180°F) [standard]
Valve lift: More than 10.0 mm/95°C
(0.394 in/203°F)
SL C3 43

EC-418Revision: August 2007
DTC P1217 ENGINE OVER TEMPERATURE
2004 QX56
5. CHECK INTERMITTENT INCIDENT
Perform EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness connectors.
Main 12 Causes of OverheatingUBS00H8Z
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to CO-4, "
OVERHEATING CAUSE ANALYSIS" . 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 mixtureMA-10, "RECOM-
MENDED FLUIDS AND
LUBRICANTS"
3
Coolant level
Visual Coolant up to MAX level
in reservoir tank and radi-
ator filler neckCO-8, "Changing Engine
Coolant"
4
Radiator cap
Pressure tester 59 - 98 kPa
(0.6 - 1.0 kg/cm2 , 9 - 14
psi) (Limit)CO-8, "
CHECKING RES-
ERVOIR CAP"
ON*25
Coolant leaks
Visual No leaksCO-8, "CHECKING
COOLING SYSTEM FOR
LEAKS"
ON*26
Thermostat
Touch the upper and
lower radiator hosesBoth hoses should be hotCO-17, "THERMOSTAT
AND WATER PIPING"
ON*17
Cooling fan
CONSULT-II Operating See trouble diagnosis for
DTC P1217 (EC-410,
"DTC P1217 ENGINE
OVER TEMPERA-
TURE" ).
OFF 8

Combustion gas leak
Color checker chemical
tester 4 Gas analyzerNegative —
ON*
39
Coolant temperature
gauge
Visual Gauge less than 3/4
when driving—

Coolant overflow to
reservoir tank
Visual No overflow during driving
and idlingCO-8, "Changing Engine
Coolant"
OFF*410
Coolant return from
reservoir tank to radia-
tor
Visual Should be initial level in
reservoir tankCO-8, "Changing Engine
Coolant"
OFF 11
Cylinder head
Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)EM-64, "Inspection After
Disassembly"
12
Cylinder block and pis-
tons
Visual No scuffing on cylinder
walls or pistonEM-89, "Inspection After
Disassembly"

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SQUEAK AND RATTLE TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Tapping or moving the components or pressing on them while driving to duplicate the conditions can isolate
many of these incidents. You can usually insulate the areas with felt cloth tape or insulator foam blocks from
the NISSAN Squeak and Rattle Kit (J-43980) to repair the noise.
TRUNK
Trunk noises are often caused by a loose jack or loose items put into the trunk by the owner.
In addition look for:
1. Trunk lid bumpers out of adjustment
2. Trunk lid striker out of adjustment
3. The trunk lid torsion bars knocking together
4. A loose license plate or bracket
Most of these incidents can be repaired by adjusting, securing or insulating the item(s) or component(s) caus-
ing the noise.
SUNROOF/HEADLINING
Noises in the sunroof/headlining area can often be traced to one of the following:
1. Sunroof lid, rail, linkage or seals making a rattle or light knocking noise
2. Sun visor shaft shaking in the holder
3. Front or rear windshield touching headliner and squeaking
Again, pressing on the components to stop the noise while duplicating the conditions can isolate most of these
incidents. Repairs usually consist of insulating with felt cloth tape.
OVERHEAD CONSOLE (FRONT AND REAR)
Overhead console noises are often caused by the console panel clips not being engaged correctly. Most of
these incidents are repaired by pushing up on the console at the clip locations until the clips engage.
In addition look for:
1. Loose harness or harness connectors.
2. Front console map/reading lamp lens loose.
3. Loose screws at console attachment points.
SEATS
When isolating seat noise it's important to note the position the seat is in and the load placed on the seat when
the noise is present. These conditions should be duplicated when verifying and isolating the cause of the
noise.
Cause of seat noise include:
1. Headrest rods and holder
2. A squeak between the seat pad cushion and frame
3. The rear seatback lock and bracket
These noises can be isolated by moving or pressing on the suspected components while duplicating the con-
ditions under which the noise occurs. Most of these incidents can be repaired by repositioning the component
or applying urethane tape to the contact area.
UNDERHOOD
Some interior noise may be caused by components under the hood or on the engine wall. The noise is then
transmitted into the passenger compartment.
Causes of transmitted underhood noise include:
1. Any component mounted to the engine wall
2. Components that pass through the engine wall
3. Engine wall mounts and connectors
4. Loose radiator mounting pins
5. Hood bumpers out of adjustment
6. Hood striker out of adjustment
These noises can be difficult to isolate since they cannot be reached from the interior of the vehicle. The best
method is to secure, move or insulate one component at a time and test drive the vehicle. Also, engine RPM
or load can be changed to isolate the noise. Repairs can usually be made by moving, adjusting, securing, or
insulating the component causing the noise.

EXHAUST MANIFOLD AND THREE WAY CATALYST
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Revision: August 20072004 QX56
EXHAUST MANIFOLD AND THREE WAY CATALYSTPFP:14004
Removal and InstallationEBS00ILG
REMOVAL
WA RN ING:
Perform the work when the exhaust and cooling system have cooled sufficiently.
1. Remove air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
2. Drain engine coolant from the radiator. Refer to MA-12, "
DRAINING ENGINE COOLANT" .
3. Remove engine undercover using power tool.
4. Remove the radiator and radiator hoses. Refer to CO-10, "
RADIATOR" .
5. Remove the drive belts. Refer to EM-12, "
Removal" .
6. Remove the air fuel ratio A/F sensors (right bank, left bank), using the following steps.
a. Remove engine room cover using power tool. Refer to EM-11, "
REMOVAL" .
b. Remove harness connector of each air fuel ratio A/F sensors, and harness from bracket and middle
clamp.
1. Air fuel ratio (A/F) sensor 1 (bank 2) 2. Exhaust manifold cover (bank 2) 3. Exhaust manifold (bank 2)
4. Gaskets 5. Exhaust manifold (left bank 1) 6. Exhaust manifold cover (bank 1)
7. Air fuel ratio (A/F) sensor 1 (bank 1)
WBIA0466E