2005 INFINITI QX4 engine overheat

EC-106Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
SYSTEM — ENGINE MECHANICAL & OTHER
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
Fuel Fuel tank
5
5FL-9
Fuel piping 5 5 5 5 5 5FL-3
Va p o r lo c k—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—
Air Air duct
55555 5EM-14
Air cleanerEM-14
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555EM-14
Electric throttle control actuatorEM-15
Air leakage from intake manifold/
Collector/GasketEM-15
Cranking Battery
111111
11SC-4
Generator circuitSC-17
Starter circuit 3SC-10
Signal plate 6EM-35
Park/Neutral position (PNP)
switch4AT- 1 0 4
Engine Cylinder head
55555 55 5EM-58
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-73
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va lv e
mecha-
nismTiming chain
55555 55 5EM-35
CamshaftEM-43
Intake valve
3EM-58
Exhaust valve

TROUBLE DIAGNOSIS
EC-107
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Revision: October 20052005 QX56
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-19
, EX-
3Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-22
, LU-
13 , LU-10 ,
LU-11
Oil level (Low)/Filthy oilLU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 45CO-12
Thermostat 5CO-19
Water pum pCO-17
Water galleryCO-8
Cooling fan 5CO-15
Coolant level (Low)/Contami-
nated coolant5CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS)11BL-137
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-136Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-54, "SYSTEM READINESS TEST (SRT) CODE" .
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.FUEL/T TEMP
SEN

Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V

Ignition switch: ON
(Engine stopped)

Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound.Solenoid valve makes an operating
sound.
Harness and connectors

Solenoid valve TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode Test item Condition Reference page
EVAPORATIVE
SYSTEMPURG FLOW P0441
Refer to corresponding
trouble diagnosis for
DTC.EC-304
EVP SML LEAK P0442/P1442*EC-309
EVP V/S LEAK P0456/P1456*EC-357
PURG VOL CN/V P1444EC-531
A/F SEN1A/F SEN1 (B1) P1276EC-497A/F SEN1 (B2) P1286EC-497
A/F SEN1 (B1) P1278/P1279EC-507, EC-519
A/F SEN1 (B2) P1288/P1289EC-507, EC-519
HO2S2HO2S2 (B1) P0139EC-225
HO2S2 (B1) P1146EC-415
HO2S2 (B1) P1147EC-426
HO2S2 (B2) P0159EC-225
HO2S2 (B2) P1166EC-415
HO2S2 (B2) P1167EC-426

DTC P0125 ECT SENSOR
EC-209
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00H20
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Check that “COOLAN TEMP/S” is above 10°C (50°F).
If it is above 10°C (50°F), the test result will be OK.
If it is below 10°C (50°F), go to following step.
4. 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.
5. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H21
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-210, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF 1 74 Y
BBIA0354E

DTC P1217 ENGINE OVER TEMPERATURE
EC-441
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Revision: October 20052005 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-10, "
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-12, "
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-445,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-445,
"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

IPDM E/R (Cooling fan relay)

Radiator hose

Radiator

Radiator cap

Water pump

Thermostat
For more information, refer to EC-448,
"Main 12 Causes of Overheating" .
SEF 6 21 W

EC-442Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
4. Perform “COOLING FAN” in “ACTIVE TEST” mode with CON-
SULT-II.
5. If the results are NG, go to EC-445, "
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-445,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-445,
"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.
CAUTION:
Be careful not to overheat engine.
6. If NG, go to EC-445, "
Diagnostic Procedure" .
SEF 6 46 X
SEF 6 21 W
SEF 8 82 V

DTC P1217 ENGINE OVER TEMPERATURE
EC-447
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8. CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-448, "
Main 12 Causes of Overheating" .
>>INSPECTION END
PROCEDURE A
1. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E120.
3. Check voltage between IPDM E/R terminal 22 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.

40A fusible link

Harness for open or short between IPDM E/R and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK COOLING FAN MOTOR CIRCUIT FOR OPEN OR SHORT
1. Disconnect cooling fan motor harness connector.
2. Check harness continuity between cooling fan motor terminal 1
and IPDM E/R terminal 24, cooling fan motor terminal 2 and
ground.
Refer to wiring diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4. CHECK COOLING FAN MOTOR
Refer to EC-449, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace cooling fan motor.Voltage: Battery voltage
PBIB2067E
Continuity should exist.
BBIA0446E

EC-448Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
5. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
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-6, "
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-11, "RECOM-
MENDED FLUIDS AND
LUBRICANTS"
3
Coolant level
Visual Coolant up to MAX level
in reservoir tank and radi-
ator filler neckCO-10, "Changing
Engine Coolant"
4
Radiator cap
Pressure tester 59 - 98 kPa
(0.6 - 1.0 kg/cm2 , 9 - 14
psi) (Limit)CO-10, "
CHECKING
RESERVOIR CAP"
ON*25
Coolant leaks
Visual No leaksCO-10, "CHECKING
COOLING SYSTEM FOR
LEAKS"
ON*26
Thermostat
Touch the upper and
lower radiator hosesBoth hoses should be hotCO-19, "THERMOSTAT
AND WATER PIPING"
ON*17
Cooling fan
CONSULT-II Operating See trouble diagnosis for
DTC P1217 (EC-440,
"DTC P1217 ENGINE
OVER TEMPERATURE"
).
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-10, "Changing
Engine Coolant"
OFF*410
Coolant return from
reservoir tank to radia-
tor
Visual Should be initial level in
reservoir tankCO-10, "Changing
Engine Coolant"
OFF 11
Cylinder head
Straight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)EM-63, "Inspection After
Disassembly"
12
Cylinder block and pis-
tons
Visual No scuffing on cylinder
walls or pistonEM-89, "Inspection After
Disassembly"