2011 INFINITI QX56 transmission

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

TM-12
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
COMPONENT PARTS
A/T CONTROL SYSTEM : TCM
INFOID:0000000006226740
 The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The
TCM controls the A/T.
 The TCM is integral with the control valve assembly and built into the A/T assembly.
A/T CONTROL SYSTEM : Tr ansmission Range SwitchINFOID:0000000006226741
 The transmission range switch incorpor ates four contact switches. Each contact switch transmits an ON/
OFF signal to the TCM.
 The TCM judges a select lever position from a comb ination of ON/OFF signals transmitted from each con-
tact switch.
A/T CONTROL SYSTEM : Input Speed SensorINFOID:0000000006226742
The input speed sensor detects input shaft rpm (revolutions per minute). It is located on the input side of the A/
T. Monitors revolution of sensor 1 and sensor 2 for non-standard conditions.
A/T CONTROL SYSTEM : Output Speed SensorINFOID:0000000006226743
The output speed sensor detects the revolution of t he parking gear and emits a pulse signal. The pulse signal
is transmitted to the TCM which converts it into vehicle speed.
A/T CONTROL SYSTEM : A/T Fluid Temperature SensorINFOID:0000000006226744
The A/T fluid temperature sensor detects the A/T fluid temperature and transmits a signal to the TCM.
A/T CONTROL SYSTEM : Input Clutch Solenoid ValveINFOID:0000000006226745
 The Input clutch solenoid valve is controlled by the TCM in response to signals transmitted from the trans-
mission range switch, output speed sensor and accelerato r pedal position sensor. Gears will then be shifted
to the optimum position.
 The Input clutch solenoid valve controls the input cl utch control valve in response to a signal transmitted
from the TCM.
A/T CONTROL SYSTEM : Front Brake Solenoid ValveINFOID:0000000006226746
 The front 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 front brake solenoid valve controls the front brak e control valve in response to a signal transmitted from
the TCM.
A/T CONTROL SYSTEM : Direc t Clutch Solenoid ValveINFOID:0000000006226747
 The direct clutch solenoid valve is controlled by t he TCM in response to signals transmitted from the trans-
mission range switch, output speed sensor and accelerato r pedal position sensor. Gears will then be shifted
to the optimum position.
 The direct clutch solenoid valve controls the direct clutch control valve in response to a signal transmitted
from the TCM.
Select lever position Transmission range switch
SW1 SW2 SW3 SW4
POFFOFFOFFOFF
RONOFFOFFON
NONONOFFOFF
D and M ONONONON
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

TM-16
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
STRUCTURE AND OPERATION
STRUCTURE AND OPERATION
TRANSMISSION
TRANSMISSION : Cross-Sectional ViewINFOID:0000000006226762
2WD MODELS
4WD MODELS
1. Low brake 2. Drum support 3. Reverse brake
4. Direct clutch 5. High and low reverse clutch 6. 2nd one-way clutch
7.
*1Rear carrier 8. Mid carrier 9. Input clutch
10.
*2Front sun gear 11 .*3Front carrier 12. Under drive carrier
13. 1st one-way clutch 14. Front brake 15. 2346 brake
16.
*4Input shaft 17. Torque converter 18. Oil pump
19.
*2Under drive sun gear 20.*3Under drive internal gear21.*4Front internal gear
22. Mid sun gear 23.
*1Mid internal gear 24. Rear sun gear
25. Rear internal gear 26. High and low reverse clutch hub 27. Control valve & TCM
28. Parking gear 29. Adapter case 30. Output shaft
*1: 7 and 23 are one unit.
*2: 10 and 19 are one unit.
*3: 11 and 20 are one unit.
*4: 16 and 21 are one unit.
JSDIA1852ZZ
Revision: 2010 May2011 QX56

TM-18
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
STRUCTURE AND OPERATION
TRANSMISSION : System Diagram
INFOID:0000000006226763
TRANSMISSION : System DescriptionINFOID:0000000006226764
DESCRIPTION
JSDIA0877GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONTM-19
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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With the use of 4 sets of planetary gears, A/T enabl es 7-speed transmission for forward and 1-speed transmis-
sion for backward, depending on the combination of 3 sets of multiple-disc clutches, 4 sets of multiple-disc
brakes and 2 sets of one-way clutches.
CLUTCH AND BRAKE CHART
POWER TRANSMISSION
“N” Position
JSDIA1455GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONTM-41
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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 Each planetary gear enters the state described below.
Front planetary gear
Under drive planetary gear
Rear planetary gear
Mid planetary gear
TRANSMISSION : Component DescriptionINFOID:0000000006226765
FLUID COOLER & FLUID WARMER SYSTEM
FLUID COOLER & FLUID WARMER SYSTEM : System DescriptionINFOID:0000000006226766
The A/T fluid temperature is controlled to an appropriate level by the A/T fluid cooler and A/T fluid warmer.
Name Front sun gear Front carrier Front internal gear
Condition — Output Input
Direction of rotation Counterclockwise revolution Clockwise revolution Clockwise revolution
Number of revolutions Deceleration from front internal
gear Deceleration from front internal
gear Same number of revolution as the
input shaft
Name Under drive sun gear Under drive carrier Under drive internal gear
Condition — Fixed Input/Output
Direction of rotation Counterclockwi se revolution — Clockwise revolution
Number of revolutions Acceleration from under drive inter-
nal gear —Same number of revolution as the
front carrier
Name Rear sun gear Rear carrier Rear internal gear
Condition Output Fixed Input
Direction of rotation Counterclockwi se revolution — Clockwise revolution
Number of revolutions Acceleration from rear internal
gear —Same number of revolution as the
under drive internal gear
Name Mid sun gear Mid carrier Mid internal gear
Condition Input Output Fixed
Direction of rotation Counterclockwise revolution Counterclockwise revolution —
Number of revolutions Same number of revolution as the
rear sun gear Deceleration from mid sun gear —
Name of the Part (Abbreviation) Function
Front brake (FR/B) Fastens the under drive carrier.
Input clutch (I/C) Connects the input shaft, the mid internal gear and the rear carrier.
Direct clutch (D/C) Connects the rear carrier and the rear sun gear.
High and low reverse clutch (HLR/C) Connects the rear sun gear and the mid sun gear.
Reverse brake (R/B) Fastens the rear carrier.
Low brake (L/B) Fastens the mid sun gear.
2346 brake (2346/B) Fastens the under drive sun gear.
1st one-way clutch (1st OWC) Allows the under drive carrier to turn freely in the forward direction but fastens it for reverse
rotation.
2nd one-way clutch (2nd OWC) Allows the rear sun gear to turn freely in the forward direction but fastens it for reverse ro-
tation.
Torque converter Amplifies driving force the engine, and transmits it to transmission input shaft.
Oil pump Driven by the engine, oil pump supplies oil to torque converter, control valve assembly, and
each lubricating system.
Revision: 2010 May2011 QX56