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4th Goar (E or D positionl
1. Hydraulic pressure is applied to the 4th clutch, which rotates together with the mainshaft, and the mainshaft 4th gear
rotates,
2. Power is transmitted to the countershaft 4th gear, which drives the countershaft.
3. Power is transm ifted to the f inal d rive gear, which drives the fina I driven gear and the transfer shaft drive gear (4WD).
4. The transfer shaft drive gear drives the transfer shaft and the transfer driven gear shaft {4WD).
NOTE:
. Hydraulic pressure is also applied to the 1st clutch, but since the rotation speed of 4th gear exceeds that of 1st gear,
power from 1st gear is cut off at the one-way clutch,
. The illustration shows the 4WO automatic transmission; power flow of the 2WD automatic transmission is identical
to the 4WD except for parts related to the transfer assembly.
ilTH GEAR
TOROUE CONVERTER
.TH CLUTCH
COU'{TERSHAFT
REVERSE SELECTOR HUB
REVERSE SELECTOR
FINAL DRIVEN GEAR
TRANSFEB SHAFT DRIVE GEAB I'WD)
TNANSFER SHAFT I4WDI{cont'd)
14-13
TMNSFER DRIVEN GEAR SHAFT (4WDI
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Page 531 of 1395
Electronic Control System
The electronic control svstem consists of a Powertrain Control Module (PCM), sensors, a linear solenoid, and four solenoid
valves. Shifting and lock-up are electronically controlled for comfortable driving under all conditions. The PCM is located
below the dashboard, under the kick panel on the passenger's side.
'97 - 98 Mod€ls
PGM.FIControl Sy3t6m
Throttl€ Poshion SensorSignalVehicle Sp.ed SensorSignal
Engino Coolant TamperetureService Check connectorSonsor Signrl
A/T Control Sy3tem
INTERLOCK
Shift Cont.ol
Shift ControlSolenoid valve ACONTROL UNITr
RShift ControlSolenoid Valve B
N
Linear SolenoidDr
Lock-up Control
Ds
Lock-up ControlSolenoid Valve A2
Lock-up ConirolSol6noid valvo B1
M.inshaft Spoed SensorSignel-D! Indicator Light
Count€rahaft Speedsensor SignelSelt-Oiagnosb signel
I
Sell-DiagnosisFunction
l-
{cont'd)
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Page 532 of 1395
Description
PCM
PGM.FIControl System
Throttle Position SensorSignelVehicle Speed SensorSignal
Engin€ Coolsnt TomperatureSen30r SignalService Ch€ck Connectol
A/T Control Svstem
INTERLOCK
Shift Control
Shift ConlrolSolenoid Valve ACONTROL UNITr
RShift ControlSolenoid Valve B
N
Linear SolenoidD
Lock-up Control
2
Lock-up ControlSolenoid valve A1
Lock-up ControlSolenoid Valve BOver-DriveSwitch Signal
Mainshaft Speed SensorSignalE Indicator Light
Countershaft SpeedSensor SigntlSelt-Oiagnosis SigndSelf-DiagnosisFunc{ion
O/D OFFIndicetor Light
Electronic Gontrol System (cont'd)
'99 - 00 Models
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Page 534 of 1395
Description
Electronic Control System (cont'dl
Grade Logic Control System
How it works:
The PCM compares actual driving conditions with memorized driving conditions, based on the input from the vehicle speed
sensor, the throttle position sensor, the barometric pressure sensor ('98 model). the engine coolant temperature sensor, the
brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS DETECTED
Driving Rcsisl.nce
Judgemont ot Controlling Aroa
. Normal Modo {Flrt ro.d mode}. Ascending Mode. Deacending Mode. Deceleration Mode
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Page 536 of 1395

Description
Electronic Control System (cont'd)
Descending Control
When the PCM determines that the vehicle is going down a hill in E and @ positions ('97 - 98 models). and in @ posi-
tion {'99 - 00 models), the shitt-up speed from 3rd to 4th gear and from 2nd to 3rd (when the throttle is closed) becomes
faster than the set speed for flat road driving to widen the 3rd gear and 2nd gear driving areas. This, in combination with
engine braking from the deceleration lock-up, achieves smooth driving when the vehicle is descending. There are three
descending modes with different 3rd gear driving areas and 2nd gear driving areas according to the magnitude of a gradi-
ent stored in the PCM. When the vehicle is in 4th gear, and you are decelerating when you are applying the brakes on a
steep hill, the transmission will downshift to 3rd gear, When you accelerate, the transmission will then return to higher
gear.
2ND - 3RD 3RD - 4TH
o50
F
DESCENDING MODE: Downshift Schodule
- : FLAT ROAD MODE
----'-----' I GRADUAL DESCENDING MODE
- - - - - : MEDIUM OESC€NOING MODE
. . ... : STEEP DESCENDING MODE
62 mph Vehicle sp€ed1100 km/hl
Deceleration Control
When the vehicle goes around a corner, and needs to decelerate first and then accelerate, the PCM sets the data for deceleration
control to reduce the number of times the transmission shifts. When the vehicle is decelerating from speeds above 27 mph(4i| km,ih), the PCM shifts the transmission from 4th to 2nd earlier than normal to cope with upcoming acceleration,
14-20
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Page 550 of 1395

Description
Hydraulic Flow (cont'dl
2nd Gsar
As the speed of the vehicle reaches the prescribed value. shift control solenoid valve A is turned ON by the pCM.Modulator pressure (6A) in the left end of the 1-2 shift valve is released by turning shift control solenoid valve A ON.The 1-2 shift valve is moved to the left side and uncovers the port to allow line pressure (5) to the 2-3 shift vatve. Linepressure (5) changes to 2nd clutch pressure (20) at the 2-3 shift valve, The 2nd clutch pressure {20) is appli€d to the2nd clutch. and the 2nd clutch is engaged.
Fluid flows by way of:- Line Pressure (4) + CPB Valve - Line Pressure (5) * 1-2 Shift Valve - Line pressure (S) * 2-3 Shift Valve- 2nd Clutch Pressure (20) - 2nd Clutch
The hydraulic pressure also flows to the lst clutch. However, no power is transmitted because of the one-wav ctutch.
NOTE:
. When used, "|eft" or "right" indicates direction on the hydraulic circurr_' The hydraulic circuit shows the'97 - 98 models (7 positions); the '99 - 00 models (6 positions) is similar,
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Page 551 of 1395

3. 3rd Gear
As the speed of the vehicle reaches the prescribed value. shift control solenoid valve B is turned OFF by the PCM.
Shift control solenoid valve A remains ON. Modulator pressure (6) flows to the right end of the 1-2 shift valve and the
left end of the 2-3 shift valve. The 2-3 shift valve is moved to the right side by modulator pressure (68) The 2-3 shift
valve covers the port to stop line prsssure (5) to the 2nd clutch. and uncovers the 3-4 shift valve as the 2-3 shift valve
is moved to the right side, Line pressure (5) becomes 3rd clutch pressure (30) at the 3-4 shift valve. The 3rd clutch
pressure (30) is applied to the 3rd clutch, and the 3rd clutch is engaged.
Fluid flows by way of:- Line pressure (4) - CPB Valve - Line Pressure (5) * 1-2 Shift Vaiv€ - Line Pressure (5) * 2-3 Shift Valve
- Line Pressure (5) * 3-4 Shift Valve - 3rd Clutch Pressure (30) * 3rd Clutch
The hvdraulic Dressure also flows to the 1st clutch. However, no power is trsnsmitted because of the one-way clutch.
NOTE:
. When used, "|eft" or "right" indicates direction on ths hydraulic circuit.
. The hvdraulic circuit shows the '97 - 98 models (7 positions); the'99 - 00 models (6 positions) is similar.
(cont'd)
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Page 552 of 1395

Description
Hydraulic Flow (cont'd)
4th Gear llQ! or E Posirion)
As the speed of the vehicle reaches the prescribed value. shift control solenoid valve A is turned OFF by the pCM,
Shift control solenoid valve B remains OFF. Modulator pressure (6) flows to the left end of the 1-2 shift valve and theleft end of the 3-4 shift valve. Modulator pressure (64) in the left end of the 1-2 shift valve equals modulator pressure(68) in the right end of the 1-2 shift valve. The 1-2 shift valve remains at left side by the tension of the valve spring.The 3-4 shift valve is moved to the right side by modulator pressure (6A). The 3-4 shift valve covers the pon to the 3rdclutch and uncovers the port to the 4th clutch as this valve is moved to the right side, The 4th clutch pressure (41)from the 3-4 shift valve becomes 4th clutch pressure (40) at the manual valve. The 4th clutch pressure (40) is appliedto the 4th clutch, and the 4th clutch is engaged.
Fluid flows by way of:- Line pressure (4) + CPB Valve - Line Pressure (5) + l-2 Shift Valve - Line Pressure {5) * 2-3 Shift Valve- Line Pressure (5) + 3-4 Shift Valve - 4th Clutch Pressure (41) + Manual Valve - 4th Clutch Pressure (40)+ 4th Clutch
The hydraulic pressure also flows to the lst clutch. However, no power is transmitted because of the one-wav clutch.
NOTE:
. When used, "lelt" or " tight" indicates direction on the hydraulic circuit.. The hydrau lic circuit shows the '97 - 98 models (7 positions); the '99 - 0O models (6 oositions) issimilar.
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