2004 INFINITI QX56 check engine

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

DTC P1217 ENGINE OVER TEMPERATURE
EC-417
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Revision: August 20072004 QX56
8. CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-418, "
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 24 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
body 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-419, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace cooling fan motor.Voltage: Battery voltage
WBIA0532E
Continuity should exist.
BBIA0446E

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"

DTC P1217 ENGINE OVER TEMPERATURE
EC-419
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Revision: August 20072004 QX56
Component InspectionUBS00H90
COOLING FAN MOTOR
1. Disconnect cooling fan motor harness connector.
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Cooling fan motor should operate.
If NG, replace cooling fan motor.
SEF 8 88 V

DTC P1271, P1281 A/F SENSOR 1
EC-429
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Revision: August 20072004 QX56
DTC P1271, P1281 A/F SENSOR 1PFP:22693
Component DescriptionUBS00H9F
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00H9G
Specification data are reference values.
On Board Diagnosis LogicUBS00H9H
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.
DTC Confirmation ProcedureUBS00H9I
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1271
1271
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit no activity detected

The A/F signal computed by ECM from the
A/F sensor 1 signal is constantly approx. 0V.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1 P1281
1281
(Bank 2)

EC-430Revision: August 2007
DTC P1271, P1281 A/F SENSOR 1
2004 QX56
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 0V, go to EC-434, "
Diag-
nostic Procedure" .
If the indication is not constantly approx. 0V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then
restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH)
within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec-
onds.
NOTE:

Keep the accelerator pedal as steady as possible during the cruising.

If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-434, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF 5 81 Z

EC-434Revision: August 2007
DTC P1271, P1281 A/F SENSOR 1
2004 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00H9K
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (Bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 GR/GApproximately 2.3V
76 G/LApproximately 3.1V
77 BR/BApproximately 2.3V
BBIA0354E

DTC P1272, P1282 A/F SENSOR 1
EC-437
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Revision: August 20072004 QX56
DTC P1272, P1282 A/F SENSOR 1PFP:22693
Component DescriptionUBS00H9M
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00H9N
Specification data are reference values.
On Board Diagnosis LogicUBS00H9O
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately high.
DTC Confirmation ProcedureUBS00H9P
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1272
1272
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit no activity detected

The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 5V.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1 P1282
1282
(Bank 2)