2011 INFINITI QX56 engine oil

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

TM-6
< PRECAUTION >[7AT: RE7R01B]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006226734
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
General PrecautionsINFOID:0000000006226735
Turn ignition switch OFF an d disconnect the battery cable
from the negative terminal before connecting or disconnect-
ing the A/T assembly connector. Because battery voltage is
applied to TCM even if igniti on switch is turned OFF.
 Perform “DTC (Diagnostic Trouble Code) CONFIRMATION
PROCEDURE” after performing each TROUBLE DIAGNOSIS.
If the repair is completed DTC should not be displayed in the
“DTC CONFIRMATION PROCEDURE”.
 Always use the specified brand of ATF. Refer to MA-10, "
Fluids
and Lubricants".
 Use lint-free paper not cloth rags during work.
 Dispose of the waste oil using the methods prescribed by law, ordi-
nance, etc. after replacing the ATF.
 Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to prevent the internal parts from
becoming contaminated by dirt or other foreign matter.
SEF289H
SEF217U
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

TM-48
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
LINE PRESSURE CONTROL
LINE PRESSURE CONTROL : System DiagramINFOID:0000000006226771
LINE PRESSURE CONTROL : System DescriptionINFOID:0000000006226772
 When an engine and A/T integrated control signal (engine
torque) equivalent to the engine drive force is
transmitted from the ECM to the TCM, the TC M controls the line pressure solenoid valve.
This line pressure solenoid controls the pressure regul ator 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.
 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)
Malfunction detection conditionTCM electronic substrate temperature
145
°C (293 °F) and 120 seconds
or
150 °C (302 °F)
Control at malfunction Accelerator opening: 0.5/8 or less
Normal return condition  TCM electronic substrate temperature: Less than 140
°C (284 °F)
and
 Vehicle speed: 5 km/h (3 MPH) or less
Vehicle behavior Accelerator opening: output torque of approximately 0.5/8
JSDIA1345GB
PCIA0008E
Revision: 2010 May2011 QX56

SYSTEMTM-51
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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*: This signal is transmitted via communication line.
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 t he engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressu re with high precision and a smoother shift change charac-
teristic is attained.
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure in real-time to achieve the best gear ratio.
BLIPPING CONTROL
This system makes transmission clutch engage readily by controlling (synchronizing) engine revolution
according to the (calculation of) engine revolution after shifting down.
 “BLIPPING CONTROL” functions.
- When downshifting by accelerator pedal depression.
- When downshifting by the manual mode.
PCIA0012E
PCIA0013E
JSDIA0826GB
Revision: 2010 May2011 QX56

SYSTEMTM-53
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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Input/Output Signal Chart
*: This signal is transmitted via communication line.
The TCM activates low brake solenoid valve and controls t he low brake oil pressure to the low pressure level
if the driver does not intend to start the vehicle while the vehicle is being stopped in the “D” position. Therefore,
the low brake is in the release (slip) status and the pow er transmission route of A/T is the same status as the
“N” position. This can decrease the engine load and im proves the fuel economy because the drive force of
engine is not transmitted to the output shaft of A/T.
Idle Neutral Contro l Start Condition
Idle neutral control starts when all of the following c onditions are satisfied. However, the control ends when
any one of the following conditions becomes insufficient during idle neutral control.
NOTE:
The idle neutral control is terminated or prohibited when the TCM and ECM detect that the vehicle is in any of
the conditions as per the following.
 Engine cooling water temperature and A/T fluid temperature are below or above a prescribed temperature.
 A/T malfunction occurs.
 DTC is detected.
 Fail-safe mode activates.
 Idle neutral control is performed continuously for a certain period of time.
Idle Neutral Contro l Resume Condition
Idle neutral control can be resumed when its start condition is fulfilled after any of the following operations is
performed (unless a malfunction occurs in the vehicle).
 After driving at more than a prescribed speed.
 When idle neutral control start conditions are fulfilled for a certain period of time.
SHIFT PATTERN CONTROL
Item Signal
TCM function Actuator
Each sensor, switch and
control unit ⇒ TCM TCM
⇒ ECM ECM ⇒ TCM
Input speed sensor 1, 2 Input speed
N idle instruction
signal (Standby sig- nal)* N idle instruction
signal (Start signal)* Idle neutral con-
trol Low brake sole-
noid valve
Output speed sensor Output shaft revolution
A/T fluid temperature
sensor
ATF temperature
Transmission range
switch Selector lever position
ECM Engine speed signal*
Accelerator pedal posi-
tion signal*
Throttle position signal*
BCM Stop lamp switch signal*
Turn indicator signal*
ABS actuator electric
unit (control unit) Pressure sensor signal*
Decel G sensor signal*
Combination meter Vehicle speed signal*
Driving location : Level road and gentle slope
Selector lever position : “D” position
Vehicle speed : 0 km/h (0 MPH)
Accelerator pedal opening : 0.0 / 8
Brake pedal : Depress
Engine speed : Idle speed
Snow mode switch : OFF
Turn signal lamp and ha zard warning lamp : OFF
Revision: 2010 May2011 QX56

TM-62
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
DIAGNOSIS SYSTEM (TCM)
INPUT SPEED (rpm) X X Displays the input speed calculated from front
sun gear revolution and front carrier revolution.
F SUN GR REV (rpm) — — Displays the front sun gear revolution calculat-
ed from the pulse signal of input speed sensor
1.
F CARR GR REV (rpm) — — Displays the front carrier gear revolution calcu-
lated from the pulse signal of input speed sen-
sor 2.
ENGINE SPEED (rpm) X X Displays the engine speed received via CAN
communication.
TC SLIP SPEED (rpm) — X Displays the revolution difference between in-
put speed and engine speed.
ACCELE POSI (0.0/8) X — Displays the accelerator position estimated val-
ue received via CAN communication.
THROTTLE POSI (0.0/8) X X Displays the throttle position received via CAN
communication.
ATF TEMP 1 ( °C or °F) X X Displays the ATF temperature of oil pan calcu-
lated from the signal voltage of A/T fluid tem-
perature sensor.
ATF TEMP 2 ( °C or °F) X X Displays the ATF temperature estimated value
of torque converter outlet calculated from the
signal voltage of A/T fluid temperature sensor.
ATF TEMP SE 1 (V) — — Displays the signal voltage of A/T fluid temper-
ature sensor.
BATTERY VOLT (V) X — Displays the power supply voltage of TCM.
LINE PRES SOL (A) — X Displays the command current from TCM to the
line pressure solenoid.
TCC SOLENOID (A) — X Displays the command current from TCM to the
torque converter clutch solenoid.
L/B SOLENOID (A) — X Displays the command current from TCM to the
low brake solenoid.
FR/B SOLENOID (A) — X Displays the command current from TCM to the
front brake solenoid.
HLR/C SOL (A) — X Displays the command current from TCM to the
high and low reverse clutch solenoid.
I/C SOLENOID (A) — X Displays the command current from TCM to the
input clutch solenoid.
D/C SOLENOID (A) — X Displays the command current from TCM to the
direct clutch solenoid.
2346/B SOL (A) — X Displays the command current from TCM to the
2346 brake solenoid.
L/P SOL MON (A) — — Monitors the command current from TCM to the
line pressure solenoid, and displays the moni-
tor value.
TCC SOL MON (A) — — Monitors the command current from TCM to the
torque converter clutch solenoid, and displays
the monitor value.
L/B SOL MON (A) — — Monitors the command current from TCM to the
low brake solenoid, and displays the monitor
value.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (TCM)TM-63
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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FR/B SOL MON (A) — — Monitors the command current from TCM to the
front brake solenoid, and displays the monitor
value.
HLR/C SOL MON (A) — — Monitors the command current from TCM to the
high and low reverse clutch solenoid, and dis-
plays the monitor value.
I/C SOL MON (A) — — Monitors the command current from TCM to the
input clutch solenoid, and displays the monitor
value.
D/C SOL MON (A) — — Monitors the command current from TCM to the
direct clutch solenoid, and displays the monitor
value.
2346/B SOL MON (A) — — Monitors the command current from TCM to the
2346 brake solenoid, and displays the monitor
value.
GEAR RATIO — X Displays the gear ratio calculated from input
speed and output speed.
ENGINE TORQUE (Nm) — — Displays the engine torque estimated value re-
ceived via CAN communication.
ENG TORQUE D (Nm) — — Displays the engine torque estimated value re-
flected the requested torque of each control unit
received via CAN communication.
INPUT TRQ S (Nm) — — Displays the input torque using for the oil pres-
sure calculation process of shift change control.
INPUT TRQ L/P (Nm) — — Displays the input torque using for the oil pres-
sure calculation process of line pressure con-
trol.
TRGT PRES L/P (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of torque
converter clutch solenoid valve calculated by
the oil pressure calculation process of lock-up
control.
TRGT PRES TCC (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of torque
converter clutch solenoid valve calculated by
the oil pressure calculation process of shift
change control.
TRGT PRES L/B (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of low
brake solenoid valve calculated by the oil pres-
sure calculation process of shift change control.
TRGT PRE FR/B (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of front
brake solenoid valve calculated by the oil pres-
sure calculation process of shift change control.
TRG PRE HLR/C (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of high
and low reverse clutch solenoid valve calculat-
ed by the oil pressure calculation process of
shift change control.
TRGT PRES I/C (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of input
clutch solenoid valve calculated by the oil pres-
sure calculation process of shift change control.
TRGT PRES D/C (kPa, kg/cm
2 or psi)—— Displays the target oil pressure value of direct
clutch solenoid valve calculated by the oil pres-
sure calculation process of shift change control.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56