2003 NISSAN X-TRAIL engine

OVERALL SYSTEM
AT-19
D
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Shift MechanismECS004QD
CONSTRUCTION
FUNCTION OF CLUTCH AND BRAKE
CLUTCH AND BAND CHART
1. Torque converter 2. Oil pump 3. Input shaft
4. Brake band 5. Reverse clutch 6. High clutch
7. Front sun gear 8. Front pinion gear 9. Front internal gear
10. Front planetary carrier 11. Rear sun gear 12. Rear pinion gear
13. Rear internal gear 14. Rear planetary carrier 15. Forward clutch
16. Forward one-way clutch 17. Overrun clutch 18. Low one-way clutch
19. Low & reverse brake 20. Parking pawl 21. Parking gear
22. Output shaft 23. Idle gear 24. Output gear
SAT998I
Clutch and brake components Abbr. Function
5Reverse clutch R/C To transmit input power to front sun gear7.
6High clutch H/C To transmit input power to front planetary carrier10.
15Forward clutch F/C To connect front planetary carrier10with forward one-way clutch16.
17Overrun clutch O/C To connect front planetary carrier10with rear internal gear13.
4Brake band B/B To lock front sun gear7.
16Forward one-way clutch F/O.C When forward clutch15is engaged, to stop rear internal gear13from rotating in
opposite direction against engine revolution.
18Low one-way clutch L/O.C To stop front planetary carrier10from rotating in opposite direction against
engine revolution.
19Low & reverse brake L & R/B To lock front planetary carrier10.
Shift positionRever
se
clutch
5High
clutch
6For-
ward
clutch
15Over-
run
clutch
17Band servo
Forward
one-way
clutch
16Low
one-
way
clutch
18Low &
revers
e
brake
19Lock-
upRemarks
2nd
apply3rd
releas
e4th
apply
PPA R K
POSITION
RREVERSE
POSITION

AT-20
OVERALL SYSTEM
l*1: Operates when overdrive control switch is set in “OFF” position.
l*2: Oil pressure is applied to both 2nd “apply” side and 3rd “release” side of band servo piston. However, brake band does not con-
tract because oil pressure area on the “release” side is greater than that on the “apply” side.
l*3: Oil pressure is applied to 4th “apply” side in condition *2 above, and brake band contracts.
l*4: A/T will not shift to 4th when overdrive control switch is set in “OFF” position.
l*5: Operates when overdrive control switch is “OFF”.
l:Operates.
lA: Operates when throttle opening is less than 3/16, activating engine brake.
lB: Operates during “progressive” acceleration.
lC: Operates but does not affect power transmission.
lD: Operates when throttle opening is less than 3/16, but does not affect engine brake.
POWER TRANSMISSION
“N” and “P” Positions
l“N” position
Power from the input shaft is not transmitted to the output shaft because the clutches do not operate.
l“P” position
NNEUTRAL
POSITION
D*41st *1D B B
Automatic
shift
1Û2Û3Û
4 2nd *1A B
3rd *1A *2C C B
*5
4th C *3C C
21st D B BAutomatic
shift
1Û2 2nd A B
11stBLocks (held
stationary) in
1st speed
1Ü2 2ndB Shift positionRever
se
clutch
5High
clutch
6For-
ward
clutch
15Over-
run
clutch
17Band servo
Forward
one-way
clutch
16Low
one-
way
clutch
18Low &
revers
e
brake
19Lock-
upRemarks
2nd
apply3rd
releas
e4th
apply

AT-22
OVERALL SYSTEM
“11”Position
“D
1”and“21” Positions
lForward clutch
lForward one-way clutch
lOverrun clutch
lLow and reverse brakeAs overrun clutch engages, rear internal gear is locked by the operation of low and
reverse brake.
This is different from that of D
1and 21.
Engine brake Overrun clutch always engages, therefore engine brake can be obtained when deceler-
ating.
SAT374J
lForward one-way clutch
lForward clutch
lLow one-way clutchRear internal gear is locked to rotate counterclockwise because of the functioning of
these three clutches.
Overrun clutch
engagement conditions
(Engine brake)D
1: Overdrive control switch “OFF” and throttle opening is less than 3/16
2
1: Always engaged
At D
1and 21positions, engine brake is not activated due to free turning of low one-
way clutch.

OVERALL SYSTEM
AT-25
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“D4” (OD) Position
SAT379J
lHigh clutch
lBrake band
lForward 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
4position, there is no one-way clutch in the power transmission line and engine
brake can be obtained when decelerating.

AT-26
OVERALL SYSTEM
“R” Position
SAT380J
lReverse clutch
lLow and 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.

OVERALL SYSTEM
AT-27
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Control SystemECS004QE
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.
*: This sensor means Accelerator pedal position (APP) sensor.
SAT381J
SWITCHES & SENSORS TCM ACTUATORS
PNP switch
Throttle position sensor*
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed sensor
Overdrive control switch
Stop la mp s witchShift control
Line pressure control
Lock-up control
Overrunclutchcontrol
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
controlShift 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

AT-28
OVERALL SYSTEM
CONTROL SYSTEM
TCM FUNCTION
ThefunctionoftheTCMisto:
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.
INPUT/OUTPUT SIGNAL OF TCM
SCIA0690E
Sensors, switches and solenoid
valvesFunction
InputPNP switch Detects select lever position and sends a signal to TCM.
Throttle position sensor (accelerator
pedal position(app) sensorDetects throttle valve position and sends a signal to TCM.
Engine speed signal From ECM.
A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
Revolution sensor Detects output shaft rpm and sends a signal to TCM.
Vehicle speed sensorUsed as an auxiliary vehicle speed sensor. Sends a signal when revolution
sensor (installed on transmission) malfunctions.
Overdrive control switch*1Sends a signal, which prohibits a shift to “D
4” (overdrive) position, to the
TCM.
Stop lamp switch Releases lock-up system when depressing pedal in lock-up condition.

OVERALL SYSTEM
AT-29
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Control MechanismECS004QF
LINE PRESSURE CONTROL
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.
Back-up Control (Engine brake)
If the selector lever is shifted to “2” position while driving in D4(OD)
or D
3, great driving force is applied to the clutch inside the transmis-
sion. 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.
OutputShift solenoid valve A/BSelects shifting point suited to driving conditions in relation to a signal sent
from TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in relation
to a signal sent from TCM.
Torque converter clutch solenoid
valveRegulates (or decreases) lock-up pressure suited to driving conditions in rela-
tion to a signal sent from TCM.
Overrun clutch solenoid valveControls an “engine brake” effect suited to driving conditions in relation to a
signal sent from TCM.
O/D OFF indicator lamp Shows TCM faults when A/T control components malfunction.Sensors, switches and solenoid
valvesFunction
SAT003J
SAT004J
SAT005J