Infiniti M45 (Y34). Manual - part 36

A/T CONTROL SYSTEM

AT-29

D

E

F

G

H

I

J

K

L

M

A

B

AT

“D” and “M5” Positions 5th Gear

●

The front brake fastens the front sun gear.

●

The input clutch is coupled and the front internal gear and mid internal gear are connected.

●

The high and low reverse clutch is coupled and the mid sun gear and rear sun gear are connected.

1.

Front brake

2.

Input clutch

3.

Direct clutch

4.

High and low reverse clutch

5.

Reverse brake

6.

Forward brake

7.

Low coast brake

8.

1st one-way clutch

9.

Forward one-way clutch

10. 3rd one-way clutch

11.

Front sun gear

12. Input shaft

13. Mid internal gear

14.

Front internal gear

15. Rear carrier

16. Rear sun gear

17.

Mid sun gear

18. Front carrier

19. Mid carrier

20.

Rear internal gear

21. Intermediate shaft

22. Output shaft

23.

Parking gear

24. Parking pawl

SCIA3993E

AT-30

A/T CONTROL SYSTEM

“R” Position

●

The front brake fastens the front sun gear.

●

The high and low reverse clutch is coupled and the mid sun gear and rear sun gear are connected.

●

The reverse brake fastens the rear carrier.

1.

Front brake

2.

Input clutch

3.

Direct clutch

4.

High and low reverse clutch

5.

Reverse brake

6.

Forward brake

7.

Low coast brake

8.

1st one-way clutch

9.

Forward one-way clutch

10. 3rd one-way clutch

11.

Front sun gear

12. Input shaft

13. Mid internal gear

14.

Front internal gear

15. Rear carrier

16. Rear sun gear

17.

Mid sun gear

18. Front carrier

19. Mid carrier

20.

Rear internal gear

21. Intermediate shaft

22. Output shaft

23.

Parking gear

24. Parking pawl

SCIA3994E

A/T CONTROL SYSTEM

AT-31

D

E

F

G

H

I

J

K

L

M

A

B

AT

TCM Function

ACS004PX

The function of the TCM is to:

●

Receive input signals sent from various switches and sensors.

●

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

●

Send required output signals to the respective solenoids.

CONTROL SYSTEM OUTLINE 

The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.

CONTROL SYSTEM DIAGRAM 

SENSORS (or SIGNAL)

Þ

TCM

Þ

ACTUATORS

PNP switch
Accelerator pedal position sensor
Closed throttle position signal
Wide-open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Manual mode switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switch

Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN system

Input clutch solenoid valve 
Direct clutch solenoid valve 
Front brake solenoid valve
High and low reverse clutch 
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid 
valve
Line pressure solenoid valve
A/T CHECK indicator lamp

SCIA4450E

AT-32

A/T CONTROL SYSTEM

CAN Communication

ACS004PY

SYSTEM DESCRIPTION 

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. Refer to 

LAN-21, "CAN

COMMUNICATION"

 .

Input/Output Signal of TCM

ACS004PZ

*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: Used as a condition for starting self-diagnostics; if self-diagnostics are not started, it is judged that there is some kind of error.
*5: Input by CAN communications.
*6: Output by CAN communications.

Control item

Line

pressure

control

Vehicle 

speed 

control

Shift     

control

Lock-up 

control

Engine 

brake 

control

Fail-safe 

function 

(*3)

Self-diag-

nostics 

function

Input

Accelerator pedal position signal 

(*5)

X

X

X

X

X

X

X

Vehicle speed sensor A/T
(revolution sensor)

X

X

X

X

X

X

Vehicle speed sensor MTR

(*1) (*5)

X

X

X

X

X

Closed throttle position signal

(*5)

(*2) X

(*2) X

X

(*2) X

(*4) X

Wide-open throttle position signal

(*5)

(*2) X

(*2) X

(*4) X

Turbine revolution sensor 1

X

X

X

X

Turbine revolution sensor 2
(for 4th speed only)

X

X

X

X

Engine speed signals

(*5)

X

X

PNP  switch

X

X

X

X

X

X

(*4)  X

Stop lamp switch signal

(*5)

X

X

(*4)  X

A/T fluid temperature sensors 1, 2

X

X

X

X

X

X

ASCD or ICC

Operation signal

(*5)

X

X

X

X

Overdrive cancel 

signal

(*5)

X

X

X

TCM power supply voltage signal

X

X

X

X

X

X

X

Out-
put

Direct clutch solenoid (ATF pressure 
switch 5)

X

X

X

X

Input clutch solenoid (ATF pressure 
switch 3)

X

X

X

X

High and low reverse clutch sole-
noid (ATF pressure switch 6)

X

X

X

X

Front brake solenoid (ATF pressure 
switch 1)

X

X

X

X

Low coast brake solenoid (ATF 
pressure switch 2)

X

X

X

X

X

Line  pressure  solenoid

X

X

X

X

X

X

X

TCC solenoid

X

X

X

Self-diagnostics table

(*6)

X