NISSAN NAVARA 2005 Repair Owner's Guide

A/T CONTROL SYSTEM
AT-23
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“D” and “3” Positions 3rd Gear
lThe front brake fastens the front sun gear.
lThe direct clutch is coupled, and the rear carrier and rear sun gear are connected.
lThe 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
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AT-24
A/T CONTROL SYSTEM
“D” Position 4th Gear
lThe direct clutch is coupled, and the rear carrier and rear sun gear are connected.
lThe high and low reverse clutch is coupled and the mid sun gear and rear sun gear are connected.
lThe input clutch is coupled and the front internal gear and mid internal gear are connected.
lThe 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
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A/T CONTROL SYSTEM
AT-25
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“D” Position 5th Gear
lThe front brake fastens the front sun gear.
lThe input clutch is coupled and the front internal gear and mid internal gear are connected.
lThe 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
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AT-26
A/T CONTROL SYSTEM
“R” position
lThe front brake fastens the front sun gear.
lThe high and low reverse clutch is coupled and the mid sun gear and rear sun gear are connected.
lThe 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
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TCM FunctionECS00FWI
The function of the TCM is to:
lReceive input signals sent from various switches and sensors.
lDetermine required line pressure, shifting point, lock-up operation, and engine brake operation.
lSend required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The A/T senses vehicle operating conditions through various sensors or signals. It always controls the opti-
mum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)

TCM

ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
1st position switch signal
Overdrive control switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switchShift 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 systemInput 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
OD OFF indicator lamp
Starter relay
Back-up lamp relay
SCIA7332E

AT-28
A/T CONTROL SYSTEM
CAN Communication
ECS00FWJ
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 toLAN-30,
"CAN Communication Unit".
Input/Output Signal of TCMECS00FWK
*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 itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXXX X
Vehicle speed sensor A/T
(revolution sensor)XXXXXX 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)XX(*4)
Turbine revolution sensor 1 X X X X X
Turbine revolution sensor 2
(for 4th speed only)XXXXX
Engine speed signals
(*5)XXXXXX X
Stop lamp switch signal
(*5)XXX X(*4)
A/T fluid temperature sensors 1, 2 X X X X X X
ASCDOperation signal
(*5)XXX
Overdrive cancel signal
(*5)X
OutputDirect clutch solenoid
(ATF pressure switch 5)XX X X
Input clutch solenoid
(ATF pressure switch 3)XX X X
High and low reverse clutch solenoid
(ATF pressure switch 6)XX X X
Front brake solenoid
(ATF pressure switch 1)XX X X
Low coast brake solenoid
(ATF pressure switch 2)XX XX X
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Self-diagnosis table
(*6)X
Starter relayXX

A/T CONTROL SYSTEM
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Line Pressure ControlECS00FWL
lWhen 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.
lThis 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
PAT T E R N
lThe TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.
lIn 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 A/T is
shifted down, the line pressure is set according to the vehicle speed.
PCIA0007E
PCIA0008E
PCIA0009E

AT-30
A/T CONTROL SYSTEM
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 ControlECS00FWM
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.
PCIA0010E
PCIA0011E
PCIA0012E

A/T CONTROL SYSTEM
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SHIFT CHANGE
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 movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlECS00FWN
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
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.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
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.
PCIA0013E
selector lever “D” position “3” position “2” position
Gear position 5 4 3 2
Lock-up´–´´
PCIA0014E

AT-32
A/T CONTROL SYSTEM
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 converter clutch solenoid is varied to gradually 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 status, the torque converter clutch piston operating pressure is increased and the coupling is
completed smoothly.
Engine Brake ControlECS00FWO
lThe forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
lThe operation of the low coast brake solenoid switches the low coast brake switching valve and controls
the coupling and releasing of the low coast brake.
The low coast brake reducing valve controls the low coast brake coupling force.
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