Nissan Pathfinder (2007 year). Manual - part 7

A/T CONTROL SYSTEM

AT-27

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2007 Pathfinder

“D” and “3” Positions 3rd Gear

●

The front brake fastens the front sun gear.

●

The direct clutch is coupled, and the rear carrier and rear sun 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. Output shaft

22. Parking gear

23. Parking pawl

SCIA1516E

AT-28

A/T CONTROL SYSTEM

2007 Pathfinder

“D” Position 4th Gear

●

The direct clutch is coupled, and the rear carrier and rear sun gear are connected.

●

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

●

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

●

The drive power is conveyed to the front internal gear, mid internal gear, and rear carrier and the three
planetary gears rotate forward as one unit.

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. Output shaft

22. Parking gear

23. Parking pawl

SCIA1517E

A/T CONTROL SYSTEM

AT-29

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2007 Pathfinder

“D” Position 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. Output shaft

22. Parking gear

23. Parking pawl

SCIA4984E

AT-30

A/T CONTROL SYSTEM

2007 Pathfinder

“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. Output shaft

22. Parking gear

23. Parking pawl

SCIA1519E

A/T CONTROL SYSTEM

AT-31

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2007 Pathfinder

TCM Function

ECS00EEO

The function of the TCM is to:

●

Receive input signals sent from various switches and sensors.

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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 SIGNALS)

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
Stop lamp switch signal
Turbine revolution sensor
1st position switch signal
Overdrive control switch signal
ATF pressure switch signal

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
O/D OFF indicator lamp
Starter relay
Back-up lamp relay

SCIA6495E

AT-32

A/T CONTROL SYSTEM

2007 Pathfinder

CAN Communication

ECS00EEP

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. For details, refer to 

LAN-49,

"CAN System Specification Chart"

 .

Input/Output Signal of TCM

ECS00EEQ

*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-diagnosis; if self-diagnosis 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

X

Vehicle speed sensor MTR

(*1) (*5)

X

Closed throttle position signal

(*5)

X

(*2)

X

X

X

X

(*4)

Wide open throttle position signal

(*5)

X

X

(*4)

Turbine revolution sensor 1

X

X

X

X

X

Turbine revolution sensor 2
(for 4th speed only)

X

X

X

X

X

Engine speed signals

(*5)

X

X

X

X

X

X

X

Stop lamp switch signal

(*5)

X

X

X

X

(*4)

A/T fluid temperature sensors 1, 2

X

X

X

X

X

X

ASCD

Operation signal

(*4)

X

X

X

Overdrive cancel 

signal

(*5)

X

Output

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-diagnosis table

(*6)

X

Starter relay

X

X

A/T CONTROL SYSTEM

AT-33

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2007 Pathfinder

Line Pressure Control

ECS00EER

●

When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the
TCM controls the line pressure solenoid.

●

This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state.

LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC 
PATTERN 

●

The TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.

●

In order to obtain the most appropriate line pressure characteristic 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)

When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.

PCIA0007E

PCIA0008E

PCIA0009E

AT-34

A/T CONTROL SYSTEM

2007 Pathfinder

During Shift Change

The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.

At Low Fluid Temperature

When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.

Shift Control

ECS00EES

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 the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.

SHIFT CHANGE 

The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.

PCIA0010E

PCIA0011E

PCIA0012E