2011 INFINITI QX56 clutch

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-55
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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Input/Output Signal Chart
*: This signal is transmitted via CAN communication line.
 When driving on an up/down slope ASC judges up/down slope according to engine torque data transmitted from the ECM and vehicle speed.
Fixing at 4GR, 5GR or 6GR on an up-slope prevents sh ift hunting and controls the vehicle to gain optimum
driving force. On a down-slope, automatic shift-down to 4GR, 5GR or 6GR controls to gain optimum engine
brake.
 When driving on a curve TCM receives the side G sensor signal from the ABS ac tuator and electric unit (control unit). It locks to 4GR,
5GR or 6GR position in moderate cornering or to 3G R position in sharp cornering based on this signal. This
prevents any upshift and kickdown during corner ing, maintaining smooth vehicle travel.
To w M o d e
 High driving torque is required for towing a heavy load. The tow mode enables torque-oriented driving by
changing the shift schedule to that of delaying A/T gear shift timing (compared to normal driving).
 TCM receives tow mode switch signal from combination meter via CAN communication. The tow mode turns ON when TCM receives the signal. TCM transmits a tow mode indicator lamp signal to the combination
meter via CAN communication to turn ON the tow mode indicator lamp mounted in the combination meter.
MANUAL MODE
Item Signal TCM function Actuator
Input speed sensor 1, 2 Input speed
ASC (Adaptive shift control)  High and low reverse
clutch solenoid valve
 Direct clutch solenoid valve
 Input clutch solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Front brake solenoid valve
 Torque converter clutch so- lenoid valve
 Line pressure solenoid valve
 Anti-interlock solenoid
valve
Output speed sensor Vehicle speed
A/T fluid temperature sensor ATF temperature
ECM
Engine speed signal*
Accelerator pedal position signal*
Closed throttle position signal*
Engine and A/T integrated control signal
(engine torque)*
ABS actuator and electric unit
(control unit) Side G sensor signal*
BCM Stop lamp switch signal*
Combination meter Tow mode switch signal*
JSDIA1362GB
Revision: 2010 May2011 QX56

TM-56
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
Input/Output Signal Chart
*: This signal is transmitted via CAN communication line.
 The TCM receives the manual mode signal, non-manual mode signal, manual mode shift up signal and
manual mode shift down signal from combination meter via CAN communication line. The TCM shifts shift
pattern control to the manual mode based on these signal s, and then shifts the A/T by operating each sole-
noid valve according to the shift operation of the driver.
 The TCM prohibits the manual mode while being in fail-safe mode due to an A/T malfunction, etc. Refer to TM-74, "
Fail-Safe".
Manual Mode Information
 The TCM transmits the manual mode shift refusal signal to the combination meter if the TCM refuses the
transmission from the driving status of vehicle when the selector lever shifts to “UP (+ side)” or “DOWN (−
side)” side. The combination meter blinks shift indicator on the combination meter and sounds the buzzer to
indicate the driver that the shifting is not performed when receiving this signal. However, the TCM does not
transmit the manual mode shift refusal signal in the conditions as per the following.
- When the selector lever shifts to “DOWN ( − side)” side in 1GR.
- When the selector lever shifts to “UP (+ side)” side in 7GR.
LOCK-UP CONTROL
LOCK-UP CONTROL : System DiagramINFOID:0000000006226777
LOCK-UP CONTROL : System DescriptionINFOID:0000000006226778
 The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
 Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
 The torque converter clutch control valve operation is controlled by the torque converter 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.
Item Signal TCM function Actuator
Output speed sensor Vehicle speed
Manual mode High and low reverse clutch
solenoid valve
 Direct clutch solenoid valve
 Input clutch solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Front brake solenoid valve
 Torque converter clutch sole- noid valve
 Line pressure solenoid valve
 Anti-interlock solenoid valve
A/T fluid temperature sensor ATF temperature
ECM
Engine speed signal*
Accelerator pedal position sig-
nal*
Combination meter Manual mode signal*
Non-manual mode signal*
Manual mode shift up signal*
Manual mode shift down signal*
JSDIA1350GB
Revision: 2010 May2011 QX56

SYSTEMTM-57
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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O PLock-up Operation Condition Table
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
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 this 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 steadily 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 states, the torque conv erter 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 fo r 2GR, 3GR, 4GR, 5GR, 6GR and 7GR.
A/T SHIFT LOCK SYSTEM
JSDIA0847GB
Selector lever “D” position “M” position
Gear position 765432765432
Lock-up×––––– ××××××
Slip lock-up ××××××××××××
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

DIAGNOSIS SYSTEM (TCM)TM-65
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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ASCD-OD CUT (ON/OFF) X — Displays the reception status of ASCD OD can-
cel request signal received via CAN communi-
cation.
ASCD-CRUISE (ON/OFF) X — Displays the reception status of ASCD opera-
tion signal received via CAN communication.
ABS SIGNAL (ON/OFF) X — Displays the re
ception status of ABS operation
signal received via CAN communication.
TCS GR/P KEEP (ON/OFF) X — Displays the reception status of TCS gear keep
request signal received via CAN communica-
tion.
TCS SIGNAL 2 (ON/OFF) X — Displays whether the reception value of A/T
shift schedule change demand signal received
via CAN communication is “cold”.
TCS SIGNAL 1 (ON/OFF) X — Displays whether the reception value of A/T
shift schedule change demand signal received
via CAN communication is “warm”.
LOW/B PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of low
brake.
HC/IC/FRB PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of high
and low reversed clutch, input clutch or front
brake.
IC/FRB PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of input
clutch or front brake.
HLR/C PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of high
and low reversed clutch.
W/O THL POS (ON/OFF) X — Displays the kickdown condition signal status
received via CAN communication.
CLSD THL POS (ON/OFF) X — Displays the idling status signal status received
via CAN communication.
DRV CST JUDGE (DRIVE/COAST) — — Displays the judgment results of “driving” or
“coasting” judged by TCM.
SHIFT IND SIGNAL — — Displays the transmission value of shift position
signal transmitted via CAN communication.
STARTER RELAY (ON/OFF) — — Displays the command status from TCM to
starter relay.
F-SAFE IND/L (ON/OFF) — — Displays the transmission status of A/T CHECK
indicator lamp signal transmitted via CAN com-
munication.
ATF WARN LAMP (ON/OFF) — — Displays the transmission status of ATF tem-
perature signal transmitted via CAN communi-
cation.
MANU MODE IND (ON/OFF) — — Displays the transmission status of manual
mode signal transmitted via CAN communica-
tion.
ON OFF SOL MON (ON/OFF) — — Monitors the command value from TCM to the
anti-interlock solenoid, and displays the moni-
tor status.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56

TM-66
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
DIAGNOSIS SYSTEM (TCM)
DTC & SRT CONFIRMATION
START RLY MON (ON/OFF) — — Monitors the command value from TCM to the
starter relay, and displays the monitor status.
ON OFF SOL (ON/OFF) — — Displays the command status from TCM to anti-
interlock solenoid.
SLCT LVR POSI — X Displays the shift positions recognized by TCM.
GEAR — X Displays the current transmission gear position
recognized by TCM.
NEXT GR POSI — — Displays the target gear position of gear
change that is calculated based on the vehicle
speed information and throttle information.
SHIFT MODE — — Displays the transmission driving mode recog-
nized by TCM.
D/C PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of di-
rect clutch.
FR/B PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of front
brake.
2346/B PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of 2346
brake.
2346B/DC PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of 2346
brake or direct clutch.
N IDLE STATUS (ON/OFF) — — Displays the control status of idle neutral con-
trol.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56