2011 INFINITI QX56 torque

STC-6
< SYSTEM DESCRIPTION >
SYSTEM
OPERATION PRINCIPLE
During Parking (When Turning The Steering Wheel To The Right.)
1. Power steering solenoid valve is closed while a vehicle is stopped.
2. Pinion “1R”, “2R” and “3R” are closed depending on steering torque of steering wheel.
3. Oil pressure “P” in the gear housing assembly is the sum of oil pressures occurred in “2R” and “3R”. Thisresults in a light steering force because of high pressure.
During High-speed Operation
1. Power steering solenoid valve is opened during high-speed operation.
2. Pinion “1R”, “2R” and “3R” are closed depending on steering torque of steering wheel.
3. Oil pressure “2R” does not occur because the pow er steering solenoid valve is on full throttle.
4. Oil pressure “P” in the gear housing assembly includes only oil pressure occurred in “3R” and results in a heavy steering force.
EPS SYSTEM : Fail-Safe INFOID:0000000006256120
EPS system
 EPS system enters the fail-safe mode (that allows the steering
force to be controlled without impairi ng the drivability) if any of the
input/output values to/from EPS system (power steering control
unit) deviate from the standard range.
 The power steering control unit controls the driving voltage to the
power steering solenoid valve for maintaining the power steering
assist force when the fail-safe function is activated. (The engine
speed signals control EPS system if any vehicle speed signal error
is detected.)
1. Combination meter 2. Power steering control unit 3. Power steering solenoid valve
4. Steering gear assembly 5. Gear housing assembly 6. Gear sub-assembly
7. Pinion 8. Power steering oil pump 9. Reservoir tank
JSGIA0020GB
JSGIA0021GB
JPGIB0022GB
Revision: 2010 May2011 QX56

STC-22
< SYMPTOM DIAGNOSIS >
UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION)
SYMPTOM DIAGNOSIS
UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIA-
TION)
Description INFOID:0000000006256131
 Hard steering when fully turning the steering wheel.
 Light steering when driving at a high speed.
Diagnosis Procedure INFOID:0000000006256132
1.CHECK SYSTEM FOR POWER SUPPLY AND GROUND
Perform trouble diagnosis for power supply and ground. Refer to STC-14, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK SYSTEM FOR VEHICLE SPEED SIGNAL
Perform trouble diagnosis for vehicle speed signal. Refer to STC-20, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK SYSTEM FOR ENGINE SPEED SIGNAL
Perform trouble diagnosis for engine speed signal. Refer to STC-18, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK SYSTEM FOR POWER STEERING SOLENOID VALVE
Perform trouble diagnosis for power steering solenoid valve. Refer to STC-16, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> Perform the symptom diagnosis for the steering system. Refer to ST-29, "NVH Troubleshooting
Chart".
NO >> Repair or replace error-detected parts.
Revision: 2010 May2011 QX56

TM-1
TRANSMISSION & DRIVELINE
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CONTENTS
TRANSAXLE & TRANSMISSION
7AT: RE7R01B
PRECAUTION ................ ...............................
6
PRECAUTIONS .............................................. .....6
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
6
General Precautions .................................................6
Service Notice or Precaution .....................................7
PREPARATION ............................................8
PREPARATION .............................................. .....8
Special Service Tool ........................................... ......8
Commercial Service Tool ..........................................9
SYSTEM DESCRIPTION .............................10
COMPONENT PARTS ................................... ....10
A/T CONTROL SYSTEM ...........................................10
A/T CONTROL SYSTEM : Component Parts Lo-
cation ................................................................... ....
10
A/T CONTROL SYSTEM : Component Descrip-
tion ...................................................................... ....
11
A/T CONTROL SYSTEM : TCM .............................12
A/T CONTROL SYSTEM : Transmission Range
Switch .................................................................. ....
12
A/T CONTROL SYSTEM : Input Speed Sensor .....12
A/T CONTROL SYSTEM : Output Speed Sensor ....12
A/T CONTROL SYSTEM : A/ T Fluid Temperature
Sensor ................................................................. ....
12
A/T CONTROL SYSTEM : Input Clutch Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : Front Brake Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : Direct Clutch Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : High and Low Reverse
Clutch Solenoid Valve ......................................... ....
13
A/T CONTROL SYSTEM : Low Brake Solenoid
Valve .................................................................... ....
13
A/T CONTROL SYSTEM : Anti-interlock Solenoid
Valve ........................................................................
13
A/T CONTROL SYSTEM : 2346 Brake Solenoid
Valve ........................................................................
13
A/T CONTROL SYSTEM : Torque Converter
Clutch Solenoid Valve ......................................... ....
13
A/T CONTROL SYSTEM : Line Pressure Solenoid
Valve .................................................................... ....
13
A/T CONTROL SYSTEM : Accelerator Pedal Po-
sition Sensor ........................................................ ....
13
A/T CONTROL SYSTEM : Manual Mode Switch ....13
A/T CONTROL SYSTEM : To w Mode Switch .........14
A/T CONTROL SYSTEM : A/T CHECK Indicator
Lamp .................................................................... ....
14
A/T CONTROL SYSTEM : Tow Mode Indicator
Lamp .................................................................... ....
14
A/T CONTROL SYSTEM : Selector Lever Position
Indicator ............................................................... ....
14
A/T SHIFT LOCK SYSTEM ................................... ....14
A/T SHIFT LOCK SYSTEM : Component Parts
Location ...................................................................
15
A/T SHIFT LOCK SYSTEM : Component Descrip-
tion ...........................................................................
15
STRUCTURE AND OPERATION .....................16
TRANSMISSION .................................................... ....16
TRANSMISSION : Cross-Sectional View ................16
TRANSMISSION : System Diagram ........................18
TRANSMISSION : System Description ...................18
TRANSMISSION : Component Description .............41
FLUID COOLER & FLUID WARMER SYSTEM .... ....41
FLUID COOLER & FLUID WARMER SYSTEM :
System Description ..................................................
41
SYSTEM ............................................................44
A/T CONTROL SYSTEM ....................................... ....44
Revision: 2010 May2011 QX56

TM-3
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Description ..........................................................
..
114
DTC Logic .............................................................114
Diagnosis Procedure .............................................115
P0730 INCORRECT GEAR RATIO ..................116
Description .......................................................... ..116
DTC Logic .............................................................116
Diagnosis Procedure .............................................116
P0731 1GR INCORRECT RATIO .....................118
Description .......................................................... ..118
DTC Logic .............................................................118
Diagnosis Procedure .............................................119
P0732 2GR INCORRECT RATIO .....................120
Description .......................................................... ..120
DTC Logic .............................................................120
Diagnosis Procedure .............................................121
P0733 3GR INCORRECT RATIO .....................122
Description .......................................................... ..122
DTC Logic .............................................................122
Diagnosis Procedure .............................................123
P0734 4GR INCORRECT RATIO .....................124
Description .......................................................... ..124
DTC Logic .............................................................124
Diagnosis Procedure .............................................125
P0735 5GR INCORRECT RATIO .....................126
Description .......................................................... ..126
DTC Logic .............................................................126
Diagnosis Procedure .............................................127
P0740 TORQUE CONVERTER ........................128
DTC Logic ........................................................... ..128
Diagnosis Procedure .............................................128
P0744 TORQUE CONVERTER ........................129
Description .......................................................... ..129
DTC Logic .............................................................129
Diagnosis Procedure .............................................129
P0745 PRESSURE CONTROL SOLENOID A ..131
DTC Logic ........................................................... ..131
Diagnosis Procedure .............................................131
P0750 SHIFT SOLENOID A .............................132
DTC Logic ........................................................... ..132
Diagnosis Procedure .............................................132
P0775 PRESSURE CONTROL SOLENOID B ..133
DTC Logic ........................................................... ..133
Diagnosis Procedure .............................................133
P0780 SHIFT ....................................................134
Description .......................................................... ..134
DTC Logic .............................................................134
Diagnosis Procedure .............................................134
P0795 PRESSURE CONTROL SOLENOID C ..136
DTC Logic ........................................................... ..136
Diagnosis Procedure ........................................... ..136
P1705 TP SENSOR .........................................137
DTC Logic ..............................................................137
Diagnosis Procedure .............................................137
P1721 VEHICLE SPEED SIGNAL ..................138
Description .............................................................138
DTC Logic ..............................................................138
Diagnosis Procedure .............................................139
P1730 INTERLOCK ........................................140
Description .............................................................140
DTC Logic ..............................................................140
Judgment of Interlock ............................................140
Diagnosis Procedure .............................................141
P1734 7GR INCORRECT RATIO ...................142
Description .............................................................142
DTC Logic ..............................................................142
Diagnosis Procedure .............................................143
P1815 M-MODE SWITCH ...............................144
DTC Logic ..............................................................144
Diagnosis Procedure .............................................144
Component Inspection (Manual Mode Switch) ......146
P2713 PRESSURE CONTROL SOLENOID D .147
DTC Logic ............................................................ ..147
Diagnosis Procedure .............................................147
P2722 PRESSURE CONTROL SOLENOID E .148
DTC Logic ..............................................................148
Diagnosis Procedure .............................................148
P2731 PRESSURE CONTROL SOLENOID F .149
DTC Logic ..............................................................149
Diagnosis Procedure .............................................149
P2807 PRESSURE CONTROL SOLENOID G .150
DTC Logic ............................................................ ..150
Diagnosis Procedure .............................................150
MAIN POWER SUPPLY AND GROUND CIR-
CUIT ................................................................
151
Diagnosis Procedure .............................................151
TOW MODE SYSTEM .....................................153
Component Function Check ..................................153
Diagnosis Procedure .............................................153
Component Inspection ...........................................155
SHIFT POSITION INDICATOR CIRCUIT ........156
Description .............................................................156
Component Function Check ..................................156
Diagnosis Procedure .............................................156
SHIFT LOCK SYSTEM ...................................157
Component Function Check ..................................157
Diagnosis Procedure .............................................157
Component Inspection (Stop Lamp Switch) ..........159
Component Inspection (Park Position Switch) ......159
Revision: 2010 May2011 QX56

TM-5
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Assembly .............................................................
..
284
Inspection ..............................................................286
MID SUN GEAR, REAR SUN GEAR, HIGH
AND LOW REVERSE CLUTCH HUB ..............
287
Exploded View .................................................... ..287
Disassembly ..........................................................287
Assembly ...............................................................289
Inspection ..............................................................291
HIGH AND LOW REVERSE CLUTCH .............292
Exploded View .................................................... ..292
Disassembly ..........................................................292
Assembly ...............................................................293
Inspection ..............................................................293
DIRECT CLUTCH .............................................294
Exploded View .................................................... ..294
Disassembly ..........................................................294
Assembly ............................................................. ..294
Inspection ..............................................................295
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... ...........................................
296
SERVICE DATA AND SPECIFICATIONS
(SDS) ...............................................................
296
General Specification .......................................... ..296
Vehicle Speed at Which Gear Shifting Occurs ......296
Vehicle Speed at Which Lock-up Occurs/Releas-
es ...........................................................................
297
Stall Speed ............................................................297
Torque Converter ..................................................297
Total End Play .......................................................298
Reverse Brake Clearance .....................................298
Front Brake Clearance ..........................................298
2346 Brake Clearance ...........................................298
Revision: 2010 May2011 QX56

PRECAUTIONSTM-7
< PRECAUTION > [7AT: RE7R01B]
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 Disassembly should be done in a clean work area.
 Use lint-free paper or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the transmission.
 Place disassembled parts in order for easier and proper assembly.
 All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.
 Gaskets, seals and O-rings should be repl aced any time the A/T is disassembled.
 It is very important to perform func tional tests whenever they are indicated.
 The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent springs
and small parts from becoming scattered or lost.
 Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
 Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings and
seals, or hold bearings and washers in place during assembly. Never use grease.
 Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
 When the A/T drain plug is removed, only some of the ATF is drained. Old ATF will remain in torque con- verter and ATF cooling system.
Always follow the procedures under “Changing” when changing ATF. Refer to TM-94, "
Changing".
 Occasionally, the parking gear may be locked with the to rque insufficiently released, when stopping the vehi-
cle by shifting the selector lever from “D” or “R” to “P” position with the brake pedal depressed.
In this case, the shock with a thud caused by the abrupt release of torque may occur when shifting the selec-
tor lever from “P” posit ion to other positions.
However, this symptom is not a malfunction which results in the damage of parts.
Service Notice or PrecautionINFOID:0000000006274263
ATF COOLER SERVICE
If ATF contains frictional material (clutches, bands, etc. ), or if an A/T is repaired, overhauled, or replaced,
inspect and clean the A/T fluid cooler mounted in the radiat or or replace the radiator. Flush cooler lines using
cleaning solvent and compressed air after repair. For A/T fluid cooler cleaning procedure, refer to TM-97,
"Cleaning". For radiator replacement, refer to CO-13, "Exploded View".
Revision: 2010 May2011 QX56

COMPONENT PARTSTM-11
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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NOTE:
The following components are included in the control valve & TCM (17).
TCM
 Input speed sensor 1, 2
 A/T fluid temperature sensor
 Transmission range switch
 Direct clutch solenoid valve
 High and low reverse clutch solenoid valve
 Input clutch solenoid valve
 Front brake solenoid valve
 Low brake solenoid valve
 Anti-interlock solenoid valve
 2346 brake solenoid valve
 Line pressure solenoid valve
 Torque converter clutch solenoid valve
A/T CONTROL SYSTEM : Component DescriptionINFOID:0000000006226739
Name Function
TCM TM-12, "
A/T CONTROL SYSTEM : TCM"
Transmission range switchTM-12, "A/T CONTROL SYSTEM : Transmission Range Switch"
Output speed sensor TM-12, "A/T CONTROL SYSTEM : Output Speed Sensor"
Input speed sensor 1
TM-12, "A/T CONTROL SYSTEM : Input Speed Sensor"Input speed sensor 2
A/T fluid temperature sensorTM-12, "
A/T CONTROL SYSTEM : A/T Fluid Temperature Sensor"
Input clutch solenoid valve TM-12, "A/T CONTROL SYSTEM : Input Clutch Solenoid Valve"
Front brake solenoid valve TM-12, "A/T CONTROL SYSTEM : Front Brake Solenoid Valve"
Direct clutch solenoid valveTM-12, "A/T CONTROL SYSTEM : Direct Clutch Solenoid Valve"
High and low reverse clutch solenoid valveTM-13, "A/T CONTROL SYSTEM : High and Low Reverse Clutch Solenoid Valve"
Low brake solenoid valve TM-13, "A/T CONTROL SYSTEM : Low Brake Solenoid Valve"
Anti-interlock solenoid valve TM-13, "A/T CONTROL SYSTEM : Anti-interlock Solenoid Valve"
2346 brake solenoid valve TM-13, "A/T CONTROL SYSTEM : 2346 Brake Solenoid Valve"
Torque converter clutch solenoid valveTM-13, "A/T CONTROL SYSTEM : Torque Converter Clutch Solenoid Valve"
Line pressure solenoid valve TM-13, "A/T CONTROL SYSTEM : Line Pressure Solenoid Valve"
Accelerator pedal position sensor TM-13, "A/T CONTROL SYSTEM : Accelerator Pedal Position Sensor"
Manual mode switch TM-13, "A/T CONTROL SYSTEM : Manual Mode Switch"
Tow mode switch TM-14, "A/T CONTROL SYSTEM : Tow Mode Switch"
A/T CHECK indicator lampTM-14, "A/T CONTROL SYSTEM : A/T CHECK Indicator Lamp"
Tow mode indicator lamp* TM-14, "A/T CONTROL SYSTEM : Tow Mode Indicator Lamp"
Selector lever position indicator TM-14, "A/T CONTROL SYSTEM : Selector Lever Position Indicator"
Stop lamp switch BRC-15, "Stop Lamp Switch"
Yaw rate/side G sensorBRC-15, "Yaw Rate/Side/Decel G sensor"
Starter relay STR-6, "System Description"
ECMEC-35, "ENGINE CONTROL SYSTEM : System Description"
BCM BCS-6, "BODY CONTROL SYSTEM : System Description"
Combination meter MWI-9, "METER SYSTEM : System Description"
ABS actuator and electric unit (control unit) BRC-16, "System Description"
Revision: 2010 May2011 QX56

COMPONENT PARTSTM-13
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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A/T CONTROL SYSTEM : High and Lo w Reverse Clutch Solenoid ValveINFOID:0000000006226748
 The high and low reverse clutch solenoid valve is controlled by the TCM in response to signals transmitted
from the transmission range switch, output speed sens or and accelerator pedal position sensor. Gears will
then be shifted to the optimum position.
 The high and low reverse clutch solenoid valve controls the high and low reverse clutch control valve in response to a signal transmitted from the TCM.
A/T CONTROL SYSTEM : Lo w Brake Solenoid ValveINFOID:0000000006226749
 The low brake solenoid valve is controlled by the TC M in response to signals transmitted from the transmis-
sion range switch, output speed sensor and accelerator pedal position sensor. Gears will then be shifted to
the optimum position.
 The low brake solenoid valve controls the low brake control valve in response to a signal transmitted from
the TCM.
A/T CONTROL SYSTEM : Anti-interlock Solenoid ValveINFOID:0000000006226750
 Anti-interlock solenoid valve prevents the simultaneous activation of the input clutch and the low brake.
 The anti-interlock solenoid valve is an ON/OFF type solenoid valve.
A/T CONTROL SYSTEM : 2 346 Brake Solenoid ValveINFOID:0000000006226751
 The 2346 brake solenoid valve is controlled by the TC M in response to signals transmitted from the trans-
mission range switch, output speed sensor and accelera tor pedal position sensor. Gears will then be shifted
to the optimum position.
 The 2346 brake solenoid valve controls the 2346 brake c ontrol valve in response to a signal transmitted from
the TCM.
A/T CONTROL SYSTEM : Torque Co nverter Clutch Solenoid ValveINFOID:0000000006226752
The torque converter clutch solenoid va lve is activated, with the gear in D2, D3, D4, D5, D6, D7, M2, M3, M4,
M5, M6 and M7 by the TCM in response to signals tr ansmitted from the output speed sensor and accelerator
pedal position sensor. Torque converter clut ch piston operation will then be controlled.
A/T CONTROL SYSTEM : Line Pressure Solenoid ValveINFOID:0000000006226753
The line pressure solenoid valve regulates the oil pum p discharge pressure to suit the driving condition in
response to a signal transmitted from the TCM.
A/T CONTROL SYSTEM : Accele rator Pedal Position SensorINFOID:0000000006226754
 The accelerator pedal position sensor is installed on the upper end of the accelerator pedal assembly.
 The accelerator pedal position sensor detects the accelerator position.
 The accelerator pedal position sensor transform the a ccelerator pedal position into output voltage, and emit
the voltage signal to the ECM. Then, the TCM receives accelerator pedal position signal from the ECM via
CAN communication.
A/T CONTROL SYSTEM : Manual Mode SwitchINFOID:0000000006226755
 The manual mode switch [mode select switch and position se lect switch (shift-up/shift-down)] is installed in
the A/T shift selector assembly.
 The mode select switch detects the position (the main shift gate side or manual shift gate side) of the selec-
tor lever and transmits a manual mode signal or a not manual mode signal to the combination meter. Then,
the TCM receives a manual mode signal or non-manual mode signal from the combination meter.
 The position select switch (shift-up) detects that the se lector lever is shifted to the shift-up side of the manual
shift gate and transmits a manual mode shift up signal to the combination meter. Then, the TCM receives a
manual mode shift up signal from the combination meter.
 The position select switch (shift-down) detects that the selector lever is shifted to the shift-down side of the
manual shift gate and transmits a manual mode shift down signal to the combination meter. Then, the TCM
receives a manual mode shift down signal from the combination meter.
Revision: 2010 May2011 QX56