NISSAN X-TRAIL 2005 Service Repair Manual

OVERALL SYSTEM
AT-27
D
E
F
G
H
I
J
K
L
MA
B
AT

“D2 ”, “22 ” and “12 ” Positions

Forward clutch

Forward one-way
clutch

Brake bandRear sun gear drives rear planetary carrier and combined front internal gear. Front internal gear now
rotates around front sun gear accompanying front planetary carrier.
As front planetary carrier transfers the power to rear internal gear through forward clutch and forward one-
way clutch, this rotation of rear internal gear increases the speed of rear planetary carrier compared with
that of the 1st speed.
Overrun clutch
engagement conditionsD
2 : Overdrive control switch “OFF” and throttle opening is less than 3/16
2
2 and 12 : Always engaged
SAT378J

AT-28
OVERALL SYSTEM

“D3 ”, “23 ” and “13 ” Positions

High clutch

Forward clutch

Forward one-way
clutchInput power is transmitted to front planetary carrier through high clutch. And front planetary carrier is con-
nected to rear internal gear by operation of forward clutch and forward one-way clutch.
This rear internal gear rotation and another input (the rear sun gear) accompany rear planetary carrier to
turn at the same speed.
Overrun clutch
engagement conditionsD
3 : Overdrive control switch “OFF” and throttle opening is less than 3/16
2
3 and 13 : Always engaged
SAT379J

OVERALL SYSTEM
AT-29
D
E
F
G
H
I
J
K
L
MA
B
AT

“D4 ” (O/D) Position

High clutch

Brake band

Forward clutch (Does not affect power
transmission)Input power is transmitted to front carrier through high clutch.
This front carrier turns around the sun gear which is fixed by brake band and makes
front internal gear (output) turn faster.
Engine brakeAt D
4 position, there is no one-way clutch in the power transmission line and engine
brake can be obtained when decelerating.
SAT380J

AT-30
OVERALL SYSTEM

“R” Position

Reverse clutch

Low & reverse brakeFront planetary carrier is stationary because of the operation of low and reverse brake.
Input power is transmitted to front sun gear through reverse clutch, which drives front
internal gear in the opposite direction.
Engine brakeAs there is no one-way clutch in the power transmission line, engine brake can be
obtained when decelerating.
SAT381J

OVERALL SYSTEM
AT-31
D
E
F
G
H
I
J
K
L
MA
B
AT

TCM FunctionECS004QE
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 transaxle senses vehicle operating conditions through various switches and sensors. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM
SWITCHES & SENSORS

TCM

ACTUATORS
PNP switch
Accelerator pedal position (APP)
sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed sensor
Overdrive control switch signal
Stop lamp switch signalShift control
Line pressure control
Lock-up control
Overrun clutch control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
control
CAN systemShift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
O/D OFF indicator lamp
SCIA4505E

AT-32
OVERALL SYSTEM

CAN CommunicationECS00CTB
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.
ABS MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive
PKIA6457E
Signals TCM ECM Combination meter
Stop lamp switch signal R T
P·N range signal R T
A/T position indicator lamp signal T R
Overdrive control switch signal R T
O/D OFF indicator signal T R
Closed throttle position signal R T
Wide open throttle position signal R T
Output shaft revolution signal T R
Engine A/T integrated control signalRT
TR
A/T self-diagnosis signal T R

OVERALL SYSTEM
AT-33
D
E
F
G
H
I
J
K
L
MA
B
AT

ESP MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive
PKIA6460E
Signals TCM ECM Combination meter
Stop lamp switch signal R T
P·N range signal R T
A/T position indicator lamp signal T R
O/D OFF indicator signal T R
Overdrive control switch signal R T
Closed throttle position signal R T
Wide open throttle position signal R T
Output shaft revolution signal T R
Engine and A/T integratedRT
TR
A/T self-diagnosis signal R T

AT-34
OVERALL SYSTEM

Input/Output Signal of TCMECS00CTC
*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.
Line Pressure ControlECS004QF

TCM has various line pressure control characteristics to match the driving conditions.

An ON-OFF duty signal is sent to the line pressure solenoid valve based on TCM characteristics.

Hydraulic pressure on the clutch and brake is electronically controlled through the line pressure solenoid
valve to accommodate engine torque. This results in smooth shift operation.
NORMAL CONTROL
The line pressure to throttle opening characteristics is set for suitable
clutch operation.
Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signalXXXXXXX
Vehicle speed sensor A/T
(Revolution sensor)XXXX XX
Vehicle speed sensor MTR
(*1)XXXX X
Closed throttle position signal
(*5)(*2) X (*2) X X (*4) X
Wide open throttle position signal
(*5)(*2) X (*2) X (*4) X
Engine speed signal X X
PNP switch XXXXXX(*4) X
Stop lamp switch signal
(*5)XXX(*4) X
A/T fluid temperature sensors X X X X X
TCM power supply voltage signal XX
Out-
putShift solenoid valve A/B X X X
Line pressure solenoid X X X
Torque converter clutch solenoid
valveXXX
Overrun clutch solenoid valve X X X X
O/D OFF indicator lamp
(*6)X
SAT003J

OVERALL SYSTEM
AT-35
D
E
F
G
H
I
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K
L
MA
B
AT

BACK-UP CONTROL (ENGINE BRAKE)
If the selector lever is shifted to “2” position while driving in D4 (O/D)
or D
3 , great driving force is applied to the clutch inside the transaxle.
Clutch operating pressure (line pressure) must be increased to deal
with this driving force.
DURING SHIFT CHANGE
The line pressure is temporarily reduced corresponding to a change
in engine torque when shifting gears (that is, when the shift solenoid
valve is switched for clutch operation) to reduce shifting shock.
AT LOW FLUID TEMPERATURE

Fluid viscosity and frictional characteristics of the clutch facing change with fluid temperature. Clutch
engaging or band-contacting pressure is compensated for, according to fluid temperature, to stabilize
shifting quality.

The line pressure is reduced below 60°C (140°F) to prevent
shifting shock due to low viscosity of A/T fluid when temperature
is low.

Line pressure is increased to a maximum irrespective of the
throttle opening when fluid temperature drops to −10°C (14°F).
This pressure rise is adopted to prevent a delay in clutch and
brake operation due to extreme drop of fluid viscosity at low
temperature.
Shift ControlECS00CTD
The shift is regulated entirely by electronic control to accommodate vehicle speed and varying engine opera-
tions. This is accomplished by electrical signals transmitted by the revolution sensor and the ECM (accelerator
pedal position sensor). This results in improved acceleration performance and fuel economy.
SAT004J
SAT005J
SAT006J
SAT007J

AT-36
OVERALL SYSTEM

CONTROL OF SHIFT SOLENOID VALVES A AND B
The TCM activates shift solenoid valves A and B according to sig-
nals from the throttle position sensor and revolution sensor to select
the optimum gear position on the basis of the shift schedule memo-
rized in the TCM.
The shift solenoid valve performs simple ON-OFF operation. When
set to “ON”, the drain circuit closes and pilot pressure is applied to
the shift valve.
RELATION BETWEEN SHIFT SOLENOID VALVES A AND B GEAR POSITIONS
CONTROL OF SHIFT VALVES A AND B
Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift
valves A and B.
The drawing above shows the operation of shift valve B. When the shift solenoid valve is “ON”, pilot pressure
applied to the end face of the shift valve overcomes spring force, moving the valve upward.
Lock-Up ControlECS00CTE
The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip to
increase power transmission efficiency. The solenoid valve is controlled by an ON-OFF duty signal sent from
the TCM. The signal is converted to an oil pressure signal which controls the torque converter clutch piston.
CONDITIONS FOR LOCK-UP OPERATION
When vehicle is driven in 3rd and 4th gear position, vehicle speed and throttle opening are detected. If the
detected values fall within the lock-up zone memorized in the TCM, lock-up is performed.
SAT008J
Shift solenoid valveGear position
D1 , 21 , 11D2 , 22 , 12D3D4 (O/D) N-P
A ON (Closed) OFF (Open) OFF (Open) ON (Closed) ON (Closed)
B ON (Closed) ON (Closed) OFF (Open) OFF (Open) ON (Closed)
SAT009J
Overdrive control switch ON OFF
Selector lever “D” position
Gear position D
4D3
Vehicle speed sensor More than set value
Throttle position sensor Less than set opening
Closed throttle position switch OFF
A/T fluid temperature sensor More than 40°C (104°F)