INFINITI QX56 2011 Factory Service Manual

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-54
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
SHIFT PATTERN CONTROL : System Diagram
INFOID:0000000006226775
SHIFT PATTERN CONTROL : System DescriptionINFOID:0000000006226776
It automatically selects the shift pattern (such as r oad environment and driving style) suitable for the various
situations so as to allow the vehicle to be driven efficiently and smoothly.
ASC (ADAPTIVE SHIFT CONTROL)
JSDIA1854GB
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-58
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
A/T SHIFT LOCK SYSTEM : System Description
INFOID:0000000006226779
The selector lever cannot be shift ed from the “P” position unless the
brake pedal is depressed while the ignition switch is set to ON. The
shift lock is unlocked by turning the shift lock solenoid ON when the
ignition switch is set to ON, the park position switch is turned ON
(selector lever is in “P” position), and the stop lamp switch is turned
ON (brake pedal is depressed) as shown in the operation chart in the
figure. Therefore, the shift lock solenoid receives no ON signal and
the shift lock remains locked if all of the above conditions are not ful-
filled. (However, selector operation is allowed if the shift lock release
button is pressed.)
SHIFT LOCK OPERATION AT “P” POSITION
When Brake Pedal Is Not Depressed (No Selector Operation Allowed)
The shift lock solenoid (A) is turned OFF (not energized) and the
solenoid rod (B) is extended with the spring when the brake pedal is
not depressed (no selector operation allowed) with the ignition
switch ON.
The connecting lock lever (C) is located at the position shown in the
figure when the solenoid rod is extended. It prevents the movement
of the detent rod (D). For these r easons, the selector lever cannot be
shifted from the “P” position.
When Brake Pedal Is Depressed (Shift Operation Allowed)
The shift lock solenoid (A) is turned ON (energized) when the brake
pedal is depressed with the ignition switch ON. The solenoid rod (B)
is compressed by the electrom agnetic force. The connecting lock
lever (C) rotates when the solenoid is activated. Therefore, the
detent rod (D) can be moved. For these reasons, the selector lever
can be shifted to other positions.
“P” POSITION HOLD MECHANI SM (IGNITION SWITCH LOCK)
JPDIA0624GB
JPDIA0612ZZ
JPDIA0613ZZ
Revision: 2010 May2011 QX56

SYSTEMTM-59
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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The shift lock solenoid (A) is not energized when the ignition switch
is in any position other than ON. In this condition, the shift mecha-
nism is locked and “P” position is held. The operation cannot be per-
formed from “P” position if the brake pedal is depressed with the
ignition switch ON when the operation system of shift lock solenoid is
malfunctioning. However, the lock lever (B) is forcibly rotated and the
shift lock is released when the shift lock release button (C) is
pressed from above. Then the sele ctor operation from “P” position
can be performed.
CAUTION:
Use the shift lock release button only when the selector lever canno t be operated even if the brake
pedal is depressed with the ignition switch ON.
D : Detent rodJPDIA0614ZZ
Revision: 2010 May2011 QX56

TM-60
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNO
STIC (OBD) SYSTEM
Diagnosis DescriptionINFOID:0000000006226780
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic syst em (OBD-II) performed by the TCM in combination
with the ECM. A malfunction is indicated by the MI (ma lfunction indicator) and is stored as a DTC in the ECM
memory and in the TCM memory.
The second is the TCM original self-diagnosis indicated by the TCM. A malfunction history is stored in the
TCM memory. The detected items are overlapped with OB D-II self-diagnostic items. For details, refer to TM-
78, "DTC Index".
OBD FUNCTION
The ECM provides emission-related on board diagnos tic (OBD-II) functions for the A/T system.
One function is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is
sent to the ECM when a malfunction occurs in the corresponding OBD-related part.
The other function is to indicate a diagnostic result by means of the MI (malfunction indicator) on the instru-
ment panel. Sensors, switches and solenoi d valves are used as sensing elements.
The MI automatically illuminates in “One or Two Trip Detection Logic” when a malfunction is sensed in relation
to A/T system parts. For details, refer to EC-52, "
DIAGNOSIS DESCRIPTION : 1st Trip Detection Logic and
Two Trip Detection Logic".
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (TCM)TM-61
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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DIAGNOSIS SYSTEM (TCM)
CONSULT-III Function (TRANSMISSION)INFOID:0000000006226781
CONSULT-III APPLICATION ITEMS
*: Although “Function Test” and “Special Function” are selectable, do not use its.
WORK SUPPORT
SELF DIAGNOSTIC RESULTS
Refer to TM-78, "DTC Index".
IGN Counter
The IGN counter is indicated in Fr eeze frame data (FFD) and indicates the number of times that the ignition
switch is turned ON after returning to the normal state from DTC.
 CAN malfunction
- The number is 0 when a malfunction is detected now.
- The number increases like 1 → 2 → 3...38 → 39 after returning to the normal condition whenever ignition
switch OFF → ON.
- The number is fixed to 39 until the self-di agnosis results are erased if it is over 39.
 Other than CAN malfunction
- The number is 0 when a malfunction is detected now.
- The number increases like 1 → 2 → 3...254 → 255 after returning to the normal condition whenever ignition
switch OFF → ON.
- The number is fixed to255 until the self-diagno sis results are erased if it is over 255.
DATA MONITOR
X: Standard, —: Not applicable, : Option
Diagnostic test mode Function
Work Support This mode enables a technician to adjust some devices faster and more accurately.
Self Diagnostic Results Retrieve DTC from ECU and display diagnostic items.
Data Monitor Monitor the input/output signal of the control unit in real time.
CAN Diagnosis This mode displays a network diagnosis result about CAN by a diagram.
CAN Diagnostic Support
Monitor It monitors the status of CAN communication.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECU Identification Display the ECU identification number (part number etc.) of the selected system.
Function Test* This mode can show results of self-diagnosis of ECU with either “OK” or “NG”. For engine, more prac-
tical tests regarding sensors/switches and/or actuators are available.
Special Function* Other results or histories, etc. that are recorded in ECU are displayed.
Item name Description
G SENSOR CALIBRATION Calibrates G sensor.
Monitored item (Unit) Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
ITEM
VHCL/S SE-A/T (km/h or mph) X X Displays the vehicle speed calculated by the
TCM from the output shaft revolution.
ESTM VSP SIG (km/h or mph) X — Displays the vehicle speed signal received via
CAN communication.
OUTPUT REV (rpm) X X Displays the output speed calculated from the
pulse signal of output speed sensor.
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