Page 688 of 2189
Description
Power Flow (cont'dl
3rd Gear (bl or bd positionl
1. Hydraulic pressure is applied to the 3rd clutch. Power from the mainshaft 3rd gear is transmitted to the countershaft3rd gear.
2. Power is transmitted to the final drive gear, which drives the tinal driven gear.
NOTE: Hydraulic pressure is also applied to the 1st clutch, but since the rotation speed of 3rd gear exceeds that of 1stgear, power from lst gear is cut off at the one-way clutch.
TOROUE CONVERTER
MAINSHAFT 3RD GEAR
MAINSHAFT
COUNTERSHAFT
3RD GEAB
3RD CLUTCH
14-10
DRIVEN GEAR
Page 690 of 2189
Description
Power Flow (cont'd)
El Po3ition
1, Hydraulic pressure is switched by the manual valve to the servo valve, which moves the reverse shift fork to thereverse position. The reverse shift fork engages with the reverse selector, reverse selector hub, and the countershaftreverse gear.
Hydraulic pressure is also applied to the 4th clutch. Power is transmitt€d from the mainshaft reverse gear via thereverse idler gear to the countershaft reverse gear.
The rotation direction of the countershaft reverse gear is changed via the reverse idler gear,
Power is transmitted to the final drive gear, which drives the final driven gear.
TOROUE
MAINSHAFT
COU TERSHAFT
REVERSE SELECTORHUBREVERSE SETICTOR
REVERSE SHIFTFORK
REVERSE IDLER
14-12
FINAL ON|VEN GEAR
Page 692 of 2189

Description
Electronic Control System (cont'd)
Shift Control
The PCM instantaneously determines which gear should be selected by various signals sent from sensors, and actuatesthe shift control solenoid valves A and B to control shifting. Also. a Grade Logic Control System has been adopted to con-trol shifting in E position while the vehicle is ascending or descending a slope, or reducing speed.
PoshionGearShift Control Solenoid
Vslve A
Shift Control Solenoid
Valve B
8,tr
1stOFFON
2ndONON
3rdONOFF
E4thOFFOFF
tr2ndONON
E-ReverseONOFF
*See page 14-31 for reverse inhibitor control description.
Lock-up Control
From sensor input signals, the PCM determines whether to turn the lock-up ON or OFF, and activates lock-up controlsolenoid valve A and/or B accordingly. The combination of driving signals to lock-up control solenoid valves A and B andthe linear solenoid pressure is shown in the table below.
Lock-up ConditionsLock-up Control
Solenoid Valvo A
Lock-up Control
Solenoid Valve B
Linoar Solonoid
Prggguro
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF * ONLow
Lock-up, FullONONHigh
LOCK-Up
during decelerationONDuty operation
OFF - ON
a
14-14
Page 694 of 2189

Description
Electronic Control System {cont'dl
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system oxtends the sngagement area of2nd gear and 3rd gear to prevent ths transmission from fr€quently shifting between 2nd and 3rd gears, and between 3rdand 4th gears, so the vehicle can run smooth and have more power when needed. There are two ascending modes withdifferent 3rd gear driving areas according to the magnitude of a gradient stored in the pCM.
NOTE:
. The PCM memory contains shift schedules between 2nd and 3rd gears, and between 3rd and 4th gears that enable thePCM's fuzzy logic to automatically select the most suitable gear according to the magnitude of a gradient. Fuzzy logic is a form of artificial intelligence that lets computers respond to changing conditions much like a humanmind would,
Dssconding Control
When the PCM determines that the vehicle is going down a hilt in E position, the shift-up speed from 3rd to 4th gearwhen th€ throftle is closed becomes faster than the set speed for flat road driving to widen the 3rd gear driving area.This, in combination with engine braking from the deceleration lock-up, achieves smooth driving when the vehicle isdescending. There are two descending modes with different downshift (4 - 3) schedules according to the magnitude of agradient stored in the PCM. When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you areapplying the brakes on a steep hill, the transmission will downshift to 3rd gear. When you accel6rate, the transmission willthen return to 4th gear.
ASCENDING MODEDESCENDING MODE
4TH SHIFTING
L.
F
CHARACTERISIICSCONTROL AREA
ff.1"11", vehicr. 3pe€dff;Tlr., vohicre speed
GRADUAL ASCENOINGCONTROL AREA
Docel6ration Control
When the vehicle goes around a corner. and needs to first decelerate and then accelerate. the rcM sets the data for decelerationcontrol to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 26 mph(41 km/h), the rcM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration.
14-16
Page 696 of 2189
Description
Electronic Control System (cont'dl
Circuit Diagram and Terminal Locations -'99 - O0 Models
GNTONSWICH,,--b. rcj
LI
LOCK.UPCONIFOLSOLEI\Q D VALVE A
LOCK UP CON'IROLSOLENODVALVEB
SH FI CONTROL
SHIFTCONTFOLSOLENOIDVALVEE
L NEAF SOLEIOIO
PG2
IGP2
v3u
vcc2
sc2
6NII ON SWICH
14-18
Page 698 of 2189
Description
Hydraulic Control (cont'dl
Msin Valve Body
The main valve body houses the manual valve, the 1-2 shift valve, the 2nd orifice control valve, the cpB valve, the modu-lator valve' the servo control valve, and the relief valve. The primary functions of the main valve body are to swatch fluidpressure on and off and to control the hydraulic pressure going to the hydraulic control svstem.
2ND ORIFICE CONTROTVALVE
1-2 SHIFT VALVE
RELIEF VALVE
CPC VAL
3-4 SHTFT V
VALVE
Socondary Valve Body
The secondary valve body is located on the main valve body. The secondary valve body houses the 2-3 shift vatve, the 3-4shift valve, the 3-4 orifice control valve, the 4th exhaust valve, and the CpC valve.
CONTROL
2.3 SHIFT VALVE
4TH EXHAUST VALV€
VALVE
14-20
VALVE
Page 700 of 2189

Description
Hydraulic Control (cont'dl
Regulator Valve
The regulator valve maintains a constant hydraulic pressure from the ATF pump to the hydraulic control system, whitealso furnishing fluid to the lubricating system and torque converter. The fluid from the ATF pump flows through B and 8,.The regulator valve has a valve orifice. The fluid entering from B flows through the orifice to the A cavity. This pressure ofthe A cavity pushes the regulator valve to the right side, and this movement of the regulator valve uncovers the fluid portto the torque converter and the relief valve. The fluid flows out to the torque converter, and the relief valve and regulatorvalve moves to the left side. According to the level of the hydraulic pressure through B, the position of the regutator vatvechanges and the amount of the fluid from B' through D and c also changes. This operation is continued. maantaining theline pressure,
NOTE: When used. "|eft" or "right" indicates direction on the illustration betow.
ENGINE NOT RUNNING
TOROUE CONVERTER
ENGINE RUNNING
To TOROUE CONVERTER Lubrication
Stator Roaction Hydraulic Prossur6 Control
Hydraulic pressure increases according to torque, are performed by the regulator valve using the stator torque reaction.The stator shaft is splined with the stator in the torque converter, and its arm end contacts the regulator sprang cap. whenthe vehicle is accelerating or climbing (Torque Convert€r Range), the stator torque reaction acts on the stator shaft, andthe stator arm pushes the regulator spring cap in the direction of the arrow in proponion to the reaction. Jne stator reac-tion spring compresses, and th€ reoulator valve moves to increase the line pressure which is regulated by the regulatorvalve. The line pressure reaches its maximum when the stator torque reaction reaches its maximum.
STATOR SHAFT ARM
REGULATOR VALVE
14-22
STATORATOR SHAFT ARM
SPRING CAP
Page 702 of 2189

Description
Hydraulic Flow
General Chart ol Hydraulic PressureATF Pump- pegurator varve -_l- Line pressure -f- Modurator pressure - Linear sorenoid
| -Clutch pressure
-Torque Converter pressure
t-Lubrication Pressure
Distribution of Hydraulic Pressur€. Regulator Valve -]- Torque Converter pressure
F_ Lubrication pressure
i- To regulate Line pressure
. Manual valve _ To select Line pressure _ clutch pressure
' Modulator Valve i/odulator pressure _ ___f_ Shift Control Solenoid Valves
F_ Lock_up Control Solenoid ValvesL_ Linear Solenoid
. 1-2 Shift Valve - l. 2-3 Shift Valve - 1- Ctutch pressure. 3-4 Shift Valve
lra
PORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSUREPORT NO.DESCRIPTION OF PRESSURE
1LINE6B
MODULATE(SHIFT CONTROL
SOLENOID VALVE B)
414TH CLUTCH
LINEMODULATE(LOCK-UP CONTROL
SOLENOID VALVE A)
56LINEAR SOLENOID
LINE6D
MODULATE(LOCK-UP CONTROL
SOLENOID VALVE B)
90TOROUE CONVEBTER
2LINE6D'
MODULATE
(LOCK-UP CONTROL
SOLENOID VALVE B)
91TOROUE CONVERTER
LINE7LINE92TOROUE CONVERTERLINE8LINE/CPC93ATF COOLER3"LINE9LINE94TOROUE CONVERTER4LIN E'101ST CLUTCH95LUBRICATION
LINE202ND CLUTCHYOTOROUE CONVERTERLINE20A2ND ACCUMULATOR97TOROUE CONVERTER5LINE99SUCTION
MODULATE303RD CLUTCHXDRAIN
6A
MODULATE(SHIFT CONTROL
SOLENOID VALVE A)
404TH CLUTCH
14-24