2010 INFINITI QX56 oil pressure

SERVICE DATA AND SPECIFICATIONS (SDS)ST-37
< SERVICE DATA AND SPECIFICATIONS (SDS)
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Steering GearINFOID:0000000005147882
Oil PumpINFOID:0000000005147883
Steering FluidINFOID:0000000005147884
Steering gear model PR26AM
Rack sliding force At the neutral point:
Range within ±
11.5 mm
(± 0.453 in) from the neutral
position
(in power ON) Area average value 147
− 211 N (14.99 − 21.52 kg-f, 33.1 − 47.52 lb-f)
Allowable variation 98 N (10 kg-f, 22 lb-f) or less
Whole area (in power OFF) Peak value
294 N (30.0 kg-f, 66 lb-f) or less
Allowable variation 147 N (16 kg-f, 35 lb-f) or less
Relief oil pressure
9.0 − 9.8 mPa (91.77 − 99.93 kg/cm2 , 1305.34 − 1421.37 psi)
Fluid capacity
Approx. 1.0 (1-1/8 US qt, 7/8 Imp qt)
Revision: April 20092010 QX56

TM-4
STALL TEST ....................................................155
Inspection and Judgment .................................... ..155
LINE PRESSURE TEST ..................................157
Inspection and Judgment .................................... ..157
ROAD TEST .....................................................159
Description ........................................................... ..159
Check Before Engine Is Started ............................159
Check At Idle ....................................................... ..159
Cruise Test - Part 1 ...............................................160
Cruise Test - Part 2 ...............................................162
Cruise Test - Part 3 ...............................................162
Vehicle Speed When Shifting Gears .....................163
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................
163
A/T POSITION .................................................164
Adjustment of A/T Position .................................. ..164
Checking of A/T Position .......................................164
ON-VEHICLE REPAIR ...............................165
SHIFT CONTROL SYSTEM ........................... .165
A/T Shift Selector Removal and Installation ..........165
AIR BREATHER HOSE .................................. .166
Removal and Installation ..................................... ..166
OIL PAN ...........................................................170
Oil Pan ................................................................. ..170
CONTROL VALVE WITH TCM ........................172
Control Valve with TCM and A/T Fluid Tempera-
ture Sensor 2 and Plug ........................................ ..
172
REAR OIL SEAL ..............................................184
Rear Oil Seal ....................................................... ..184
FLUID COOLER SYSTEM ...............................185
Exploded View ..................................................... ..185
Removal and Installation .......................................185
REMOVAL AND INSTALLATION ..............186
TRANSMISSION ASSEMBLY ........................ .186
Removal and Installation (2WD) .......................... .186
Removal and Installation (4WD) ...........................188
DISASSEMBLY AND ASSEMBLY ...........192
OVERHAUL ......................................................192
Component .......................................................... .192
Oil Channel ...........................................................199
Location of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ......................... .
201
DISASSEMBLY .............................................. ..204
Disassembly ......................................................... .204
REPAIR FOR COMPONENT PARTS ..............223
Oil Pump .............................................................. .223
Front Sun Gear, 3rd One-Way Clutch ...................225
Front Carrier, Input Clutch, Rear Internal Gear .....227
Mid Sun Gear, Rear Sun Gear, High and Low Re-
verse Clutch Hub ................................................. .
232
High and Low Reverse Clutch ..............................237
Direct Clutch .........................................................239
ASSEMBLY .................................................... ..242
Assembly (1) ........................................................ .242
Adjustment ............................................................255
Assembly (2) .........................................................257
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
265
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
265
General Specification ........................................... .265
Vehicle Speed at Which Gear Shifting Occurs .....265
Vehicle Speed at Which Lock-up Occurs/Releas-
es ......................................................................... .
266
Stall Speed ............................................................266
Line Pressure ........................................................266
Input Speed Sensor ..............................................266
Output Speed Sensor ...........................................266
Reverse Brake ......................................................266
Total End Play .......................................................267
Torque Converter ..................................................267
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-23
< FUNCTION DIAGNOSIS >
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• This line pressure solenoid controls the pressure regulat or valve as the signal pressure and adjusts the pres-
sure of the operating oil discharged from the oil pump to the line pressure most appropriate to the driving
state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC PAT-
TERN
• The TCM has stored in memory a number of patterns fo r the optimum line pressure characteristic for the
driving state.
• In order to obtain the most appropriate line pressure char acteristic to meet the current driving state, the TCM
controls the line pressure solenoid current value and thus controls the line pressure.
Normal Control
Each clutch is adjusted to the necessary pressure to match the
engine drive force.
Back-up Control (Engine Brake)
When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.
During Shift Change
PCIA0007E
PCIA0008E
PCIA0009E
Revision: April 20092010 QX56

TM-24
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000005148514
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-25
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*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000005148515
The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque conver ter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
• In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
• In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
PCIA0013E
Select lever D position4 position 3 position 2 position
G ear p osit io n 54432
Lock-up ×– ×××
Slip lock-up ××–––
PCIA0014E
Revision: April 20092010 QX56

TM-26
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
When shifting from the lock-up released state to the lock-up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In th is way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
• The current output from the TCM to the torque converte r clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch piston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
• In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the
half-clutched state. This absorbs the engine tor que fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4GR and 5GR at both low speed and when the accelerator has a low
degree of opening.
Engine Brake ControlINFOID:0000000005148516
• The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
• The operation of the low coast brake solenoid switches the low coast brake switching valve and controls the
coupling and releasing of the low coast brake.
The low coast brake reducing valve contro ls the low coast brake coupling force.
Control ValveINFOID:0000000005148517
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valve In order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regu lator valve
Pressure regulator plug
Pressure regu lator sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When the front brake is coupled, adjusts the line pressure to the optimum pressure (front
brake pressure) and supplies it to the front brake. (In 1GR, 2GR, 3GR, and 5GR, adjusts
the clutch pressure.)
Accumulator control valve Adjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-27
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FUNCTION OF PRESSURE SWITCH
Pilot valve A Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve B Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for shift change control.
Low coast brake switching valve During engine braking, supplies the line pressure to the low coast brake reducing valve.
Low coast brake reducing valve When the low coast brake is coupled, adjusts the line pressure to the optimum pressure
(low coast brake pressure) and supplies it to the low coast brake.
N-R accumulator Produces the stabilizing pressure for when N-R is selected.
Direct clutch piston switching valve Operates in 4GR and switches the direct clutch coupling capacity.
High and low reverse clutch control valve When the high and low reverse clutch is coupled, adjusts the line pressure to the opti-
mum pressure (high and low reverse clutch pressure) and supplies it to the high and low
reverse clutch. (In 1GR, 3GR, 4GR and 5GR, adjusts the clutch pressure.)
Input clutch control valve When the input clutch is coupled, adjusts the line pressure to the optimum pressure (in-
put clutch pressure) and supplies it to the input clutch. (In 4GR and 5GR, adjusts the
clutch pressure.)
Direct clutch control valve When the direct clutch is coupled, adjusts the line pressure to the optimum pressure (di-
rect clutch pressure) and supplies it to the direct clutch. (In 2GR, 3GR, and 4GR, adjusts
the clutch pressure.)
TCC control valve
TCC control plug
TCC control sleeve Switches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valve Operates during lock-up to switch the torque converter, cooling, and lubrication system
oil path.
Cool bypass valve Allows excess oil to bypass cooler circuit without being fed into it.
Line pressure relief valve Discharges excess oil from line pressure circuit.
N-D accumulator Produces the stabilizing pressure for when N-D is selected.
Manual valve Sends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name
Function
Name Function
Pressure switch 2 (LC/B) Detects any malfunction in the low coast brake hydraulic pressure. When it detects any
malfunction, it puts the system into fail-safe mode.
Revision: April 20092010 QX56

P0745 PRESSURE CONTROL SOLENOID ATM-69
< COMPONENT DIAGNOSIS >
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P0745 PRESSURE CONTROL SOLENOID A
DescriptionINFOID:0000000005148605
The line pressure solenoid valve regulates the oil pum p discharge pressure to suit the driving condition in
response to a signal sent from the TCM.
The line pressure duty cycle value is not consistent when the closed throttle position signal is “ON”.
To confirm the line pressure duty cycle at low pressu re, the accelerator (throttle) should be open until
the closed throttle posi tion signal is “OFF”.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000005148606
On Board Diagnosis LogicINFOID:0000000005148607
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0745 PC SOLENOID A” with CONSULT-III is detected under the following condi-
tions.
- When TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When TCM detects as irregular by comparing target value with monitor value.
Possible CauseINFOID:0000000005148608
• Harness or connectors (The solenoid circuit is open or shorted.)
• Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000005148609
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON” and select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
2. Engine start and wait at least 5 second.
3. If DTC is detected, go to TM-69, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000005148610
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “LINE PRES SOL” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
Item name Condition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
Item nameCondition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
Revision: April 20092010 QX56