2010 INFINITI QX56 upper

DLN-158
< DISASSEMBLY AND ASSEMBLY >[ATX14B]
TRANSFER ASSEMBLY
a. Remove all the bolts except for the two shown.
b. Remove the following from the control valve assembly:
• Clutch pressure solenoid valve
• Clutch pressure switch
• 2-4WD shift solenoid valve
• Line pressure switch
• Transfer fluid temperature sensor
c. Remove the O-rings from each solenoid valve, switch and termi- nal body.
d. Place the control valve with the lower body facing up. Remove the two bolts, and then remove the lower body and separator
plate from the upper body.
CAUTION:
Do not drop relief balls. Detach lower body carefully.
e. Make sure the reverse balls, relief balls, relief springs, accumu- lator pistons and valve springs are securely installed as shown,
and remove them.
f. Remove the retainer plates.
WDIA0198E
WDIA0199E
WDIA0200E
SDIA2126E
SDIA2127E
Revision: April 20092010 QX56

TRANSFER ASSEMBLYDLN-159
< DISASSEMBLY AND ASSEMBLY > [ATX14B]
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g. Remove each retainer plate (1), plug (2), control valve (3) and spring (4) from the upper body (5).
INSPECTION AFTER DISASSEMBLY
Shift Rod Components
• Check the working face of the shift rod and fork for wear, partialwear, bending and other abnormality. If any is found, replace with a
new one.
• Measure the clearance between the shift fork and sleeve. If it is out of specification, replace it with a new one.
Planetary Carrier
• Measure the end play of each pinion gear. If it is out of specifica-tion, replace the planetary carrier assembly with a new one.
• Check the working face of each gear and bearing for damage, burrs, partial wear, dents and other abnormality. If any is found,
replace the planetary carrier assembly with a new one.
Sun Gear
WDIA0284E
SMT009D
Specification : Less than 0.36 mm (0.0142 in)
SMT010D
Pinion gear end play : 0.1 - 0.7 mm (0.004 - 0.028 in)
PDIA0185E
Revision: April 20092010 QX56

DLN-162
< DISASSEMBLY AND ASSEMBLY >[ATX14B]
TRANSFER ASSEMBLY
• Check each control valve spring for damage or distortion. Also
check its free length, outer diameter and wire diameter. If any dam-
age or fatigue is found, replace the control valve body with a new
one. Refer to DLN-142, "
Disassembly and Assembly".
CAUTION:
Replace control valve body togeth er with clutch return spring
as a set.
Clutch
• Check the drive plate facings and driven plate for damage, cracks or other abnormality. If any abnormalities are found, replace with a
new one.
• Check the thickness of the drive plate facings and driven plate.
Refer to DLN-179, "
Inspection and Adjustment".
CAUTION:
• Measure facing thickness at 3 points to take an average.
• Check all drive and driven plates.
• Check return spring for damage or deformation.
• Do not remove spring from plate.
Return Spring
• Check the stamped mark shown. T hen, check that the free lengths,
(include thickness of plate) are within specifications. If any abnor-
mality is found, replace with a new return spring assembly of the
same stamped number. Refer to DLN-179, "
Inspection and Adjust-
ment".
ASSEMBLY
Control Valve Assembly
1. Assemble the control valve assembly with the following procedure.
CAUTION:
• Do not reuse any part that has been dropped or damaged.
• Make sure valve is assembled in the proper direction.
• Do not use a magnet because residual magnetism stays during assembly.
a. Clean the upper body (5), control valves (3) and springs (4) with cleaning agent, and dry with compressed air.
b. Dip the control valves in ATF, and apply ATF to the valve-mount- ing area of the upper body.
SMT948C
SMT949C
SDIA2176E
WDIA0284E
Revision: April 20092010 QX56

TRANSFER ASSEMBLYDLN-163
< DISASSEMBLY AND ASSEMBLY > [ATX14B]
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c. Install each control valve (3), springs (4), and plugs (2) to the upper body (5), and install retainer plates (1) to hold them in
place.
CAUTION:
• To insert control valves into upper body, place upper
body on a level surface in order to prevent flaw or dam-
age.
• Make sure each control valve is smoothly inserted.
d. Install the reverse balls, relief balls and relief springs, accumula- tor pistons and valve springs to the upper body.
e. Install the lower body and separator plate to the upper body. CAUTION:
Do not reuse separator plates.
f. With the lower body down, tighten the two bolts shown.
g. Apply ATF to the new O-rings, and install them to each solenoid valve, switch and terminal body.
CAUTION:
Do not reuse O-rings.
h. Install the following to the control valve assembly: • Clutch pressure solenoid valve
• Clutch pressure switch
• 2-4WD shift solenoid valve
• Line pressure switch
• Transfer fluid temperature sensor
Center Case
SDIA2127E
SDIA2126E
WDIA0200E
WDIA0198E
Revision: April 20092010 QX56

DLN-250
< REMOVAL AND INSTALLATION >[REAR FINAL DRIVE: R230]
REAR FINAL DRIVE
REMOVAL AND INSTALLATION
REAR FINAL DRIVE
Removal and InstallationINFOID:0000000005148935
REMOVAL
1. Remove the spare tire.
2. Drain the differential gear oil. Refer to
DLN-244, "
Changing Rear Differential Gear Oil".
3. Remove the rear stabilizer bar. Refer to RSU-23, "
Removal and Installation".
4. Remove the rear propeller shaft. Refer to DLN-196, "
Removal and Installation".
5. Remove the rear drive shafts from the rear final drive assembly and support them using suitable wire. Refer to RAX-10,
"Removal and Installation".
6. Disconnect the breather hose from the rear final drive assembly.
1. Rear final drive assembly 2. Upper stopper3. Washer
4. Lower stopper Vehicle front
WDIA0383E
LDIA0164E
Revision: April 20092010 QX56

EC-304
< COMPONENT DIAGNOSIS >[VK56DE]
P1217 ENGINE OVER TEMPERATURE
4. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to “PROCEDURE
A”.)
4.CHECK COOLING SYSTEM FOR LEAK
Refer to CO-10, "
Inspection".
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. •Hose
• Radiator
• Radiator cap
• Water pump
• Reservoir tank
5.CHECK COMPONENT PARTS
Check the following.
• RESERVOIR TANK CAP (Refer to CO-10, "
Inspection".)
• Thermostat. (Refer to CO-22, "
Removal and Installation".)
• Engine coolant temperature sensor. (Refer to EC-123, "
Component Inspection".)
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning component.
6.CHECK MAIN 13 CAUSES
If the cause cannot be isolated, go to EC-304, "
Main 13 Causes of Overheating".
>> INSPECTION END
Main 13 Causes of OverheatingINFOID:0000000005149353
SEF882V
Engine Step Inspection item EquipmentStandardReference page
OFF 1 • Blocked radiator • Blocked condenser
• Blocked radiator grille
• Blocked bumper • Visual
No blocking —
2 • Coolant mixture • Coolant tester 50 - 50% coolant mixtureCO-10
3 • Coolant level • VisualCoolant up to MAX level in
reservoir tank and radiator
filler neck CO-11, "Changing Engine
Coolant"
4 • Reservoir tank cap • Pre
ssure tester 95 - 125 kPa
(0.97 - 1.28 kg/cm2, 14 -
18 psi) (Limit) CO-10, "
Inspection"
ON*25 • Coolant leaks
• VisualNo leaks CO-10, "Inspection"
ON*26 • Thermostat • Touch the upper and
lower radiator hoses Both hoses should be hot
CO-22, "Removal and In-
stallation"
ON*17 • Cooling fan • CONSULT-IIIOperating See trouble diagnosis for
DTC P1217 ( EC-36
).
Revision: April 20092010 QX56

P2122, P2123 APP SENSOREC-367
< COMPONENT DIAGNOSIS > [VK56DE]
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P2122, P2123 APP SENSOR
Component DescriptionINFOID:0000000005149440
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerato
r pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
On Board Diagnosis LogicINFOID:0000000005149441
These self-diagnoses have the on e trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P0643, first perform the tro\
uble diagnosis for DTC P0643.
Refer to EC-289
.
FA I L - S A F E M O D E
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149442
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-367, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149443
1.CHECK GROUND CONNECTIONS
PBIB1741E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2122
2122 Accelerator pedal position
sensor 1 circuit low input An excessively low vo
ltage from the APP sen-
sor 1 is sent to ECM. • Harness or connectors
(The APP sensor 1 circuit is open or
shorted.)
• Accelerator pedal position sensor (Accelerator pedal position sensor 1)
P2123
2123
Accelerator pedal position
sensor 1 circuit high input An excessively high voltage from the APP sen-
sor 1 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
Revision: April 20092010 QX56

EC-370
< COMPONENT DIAGNOSIS >[VK56DE]
P2127, P2128 APP SENSOR
P2127, P2128 APP SENSOR
Component DescriptionINFOID:0000000005149445
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
On Board Diagn
osis LogicINFOID:0000000005149446
These self-diagnoses have the one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149447
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-370, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149448
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB1741E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2127
2127 Accelerator pedal position
sensor 2 circuit low input An excessively low voltage from the APP
sensor 2 is sent to ECM. • Harness or connectors
(APP sensor 2 circuit is open or shorted.)
(TP sensor circuit is shorted.)
• Accelerator pedal position sensor (Accelerator pedal position sensor 2)
• Electric throttle control actuator (TP sensor)
P2128
2128
Accelerator pedal position
sensor 2 circuit high input An excessively high
voltage from the APP
sensor 2 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
Revision: April 20092010 QX56