ldle Control System
Automatic Transaxle {A/Tl Gear Position Signal {A/T onlyl
This signals the ECM when the transmission is in @ or @ position.
appror. 5 V?
1 1-88
-.
87 l+)
ooooooooooooo
oooooooooooo
A26 {-}
Turn the ignition switch ON.
obsorve the A/T shift indicatorand s eiecl each positionseparately.
Soo A/T goa. position indicator in-spoqtion ls6o lection 141.
Turn the ignition switch OFF.
Connect the test hamess betweenthe ECM and connectors. Discon-nect "B" connoclorlrom the mainwire harness only, not the ECM(see page 11-37).
Turn the ignition switch ON.
Measure voltage between 87 (+ Iterminal and 426 1- ) terminal.
Subslituto . known-good ECM6nd .ech6ck. lf pr63cribod voltageia now availablo, rcplaco ths o.ig-inel ECM.
ls there approx. 5 V?
Turn the ignition switch OFF.
Reconnect "8" connector lo lhemaan wire harness.
(To page 11-89)
Transaxle
Clutch
Manual Transmission ......................
Automatic Transmission ..................
Differential
Manual Transmission
81881 engine
818C1 engine
Automatic Transmission ...............
Driveshafts
12-1
13-1
14-1
15-1
15-9
15-19
16-1
Automatic Transmission
'l4-2
14-3't 4-6
14-8
14-14
14-23
Hvdraulic Flow ...--...... 14-24
Lock-up System ........ 14-38
Eloctrical Systom
Component Location ............,...,................ I 4-45
Circuit Diagram ............. 14-46'Troubleshooting Procedures ........,..........., l4-48
Symptom-to-Component Chart
Electrical System ...... 14-50
Electrical Troubleshooting
Troubleshooting Flowchart .................... 14-52
Lock-uo Control Solenoid Valve A/8
Test .................. --.... \4-82
ReDlacement ,...,...,..,. 14-82
Shift Control Solenoid Vslve A/B
Test .................. ...... 14-83
Reolacement .............. 14-83
Transmission Control Module (TCM)*ReDlacement ........... 14-84
Mainshalt/CountershaJt SDeed Sensors
Reolacement ............. 14-85
Hydraulic Systom
Symptom-to-Component Chart
Hydraulic System
Road Test
Slall Speed
Test ..................
Fluid Level
Checking/Changing
Pressu.e Testing
Transmission
Transmission
Removal ............. ...... 14-99
lllustrated Index
Right Side Cover .................................. 1 4- 1 04
Transmission Housin9 ..................,,....... I 4-1 06
Torque Converter HousingNalve
Body .................. ... 14- 1O8
Right Side Cover
Removal ............. ...... 14-110
Transmission Housing
Removal ............. .-..-. 14-112
Torque Convener HousingNalve Body
Removal ............. ...... 14-114
Valve Caps
Description ................ 14-116
Valve Body
Repair ................ ...-.. 14-117
Valve
Assembly ...........
Oil Pump
Main Valve Body
Disassembly/lnspection/Reassembly
Regulator Valve Body
Disassembly/lnspection/Reassembly
Lock-up Valve Body
Disassembly/lnspection/Reassembly .......
Secondary Valve Body
Disassembly/lnspection/Reassembly .......
Servo Body
Disassembly/lnspection/Reassembly .......
1st-hold Accumulator/Right Side Covet
Oisassembly/lnspection/Reassembly .,..,..
Mainshaft
Disassembly/lnspection/Reassembly -.. -... 1 4- 1 29
lnsDection ................. 14- 130
Countershaft
Disassembly/lnspection/Reassembly ....... 14-132
Disassembly/Reassembly ....................... 1 4-1 33
lnsDection ................. 14-134
One-way Clutch/Parking Gear
Disassembly/lnspection .................... -.. -. 1 4-137
Sub-shaft
Disassembly/lnspection/Reassembly ....... 14-138
Disassemblv/Reassemblv ....................... 1 4-1 39
Sub-shaft Bearings
Replacement ............. l4-140
Clutch
fllustrated lndex ................. -..-...-.......... 14-1 41
Disassembly ,,,.,,........ 14-144
Reassembly .............. 14-146
Torque Converter Housing Bearings
Mainshaft Bearing/Oil Seal
Reolacement ......... 14-1 50
Countershaft Bearing Replacement .......,, 14-1 5l
Transmission Housing Bearings
Mainshsft/Countershaft Bearing
Repfacement ...-..-..14-152
Sub-shaft Bearing Replacement .............. 1 4-1 53
Reve.se ldler Gear
lnstallation ................ 14-154
Parking Brake Stopper
lnspection/Adjustment ..........................'14-'154
Transmission
Reassemblv .............,. .14_156
Toroue Converter/Drive Plate ..,..,............... 1 4- 1 63
Transmission
14-120
14-122
14-123
14-124
14-126
14-124
14-86
14-90
't4-92
14-93
14-94
lnstallation
Cooler Flushing'Shitt Cable
Removal/lnstallation ..............................
Adiustment ...-..-......-. 14-'171*Gearshift Selector
Disassembly/Reassembly .....................,. 1 4-17 2*Shift Indicator Panel
Adjustment -..........-...14-173
Throttle Control Cable
fnspection .......,..,...... 14-17 4
Adjustment .............. 14-176
14-164
14-168
14-'t 7 0
Inspection
The Automatic Transmission is a combination of a 3-e,ement torque convefter and triple-shaft electfonically controlled
automatic transmission which provides 4 speeds forward and 1 speed reverse. The entire unit is positioned in line with
the engine.
Torque Converter, Gears and Clutches
The torque converter consists of a pump, turbine and stator assembly in a single unit, The torque converter is connected
to the engine crankshaft so they turn together as a unit as the engine turns. Around the outside of the torque converter
is a ring gear which meshes with the starter pinion when the engine is being staned. The entire torque converter assem-
bly serves as a flywheel while transmitting power to the transmission mainshaft.
The transmission has three parallel shafts, the mainshaft. countershaft and sub-shaft. The mainshatt is in line with the
engine crankshaft.
The mainshaft includes the clutches for 1 st, and 2ndl4th, and gears for 3rd. 2nd, 4th, reverse and l st (3rd gear is in-
tegral with the mainshaft, while reverse gear is integral with the 4th gear).
The countershaft includes the 3rd clutch and gears Ior 3rd, 2nd,4th, reverse, lst and parking. Reverse and 4th gears
can be locked to the countershaft at its center, providing 4th gear or reverse, depending on which way the selector is moved.
The sub-shaft includes the lst-hold clutch and gears for 1st and 4th
The gears on the mainshait are in constant mesh with those on the countershaft and sub-shaft. When certain combina-
tions of gears in the transmission are engaged by the clutches, power is transmitted from the mainshaft to the counter-
shaft via the sub-shatt to provide @, E, tr. tr and @ position.
Electronic Control
The electronic control system consists of the Transmission Control Module {TCM), sensors, and 4 solenoid valves. Shift-
ing and lock-up are electronically controlled for comfortable driving under all conditions.
The TCM is located below the dashboard, behind the left side kick panel on the driver's side.
Hydraulic Control
The valve bodies include the main valve body, secondary valve body, regulator valve body. servo body, and lock-up valve
body throuqh the respective separator plates.
They are bolted on the torque converter housing.
The main valve body contains the manual valve, 1-2 shift valve, 2-3 shift valve, Clutch Pressure Cont.ol (CPC) valve,
4th exhaust valve, relief valve, and oil pump gears.
The secondary valve body contains the 4-3 kick-down valve,3-2 kick-down valve,2-3 orifice cont.ol valve, 3-4 shitt
valve, orifice control valve. modulator valve, and servo control valve
The regulator valve body contains the pressure regulator valve. lock-up control valve, torque converter check valve, and
cooler check valve.
The servo bodv contains the servo valve which is integrated with the reverse shift fork, throttle valve B, and accumulators.
The lock-ug valve bodv contains the lock-up shift valve and lock-up timing B valve. and is bolted on the secondary valve
body.
Fluid from the regulator passes through the manual valve to the various control valves.
Shitt Control Mochanism
Input to the TCM i.om various sensors located throughout the car determines which shift control solenoid valve should
be activated.
Activating a shift control solenoid valve changes modulator pressure, causing a shift valve to move. This pressurizes
a line to one of the clutches. engaging that clutch and its corresponding gear.
Lock-up Mechanism
In @ position. in 2nd, 3rd and 4th, and E position in 3rd, pressurized tluid can be drained from the back of the tor-
que converter through an oil passage, causing the lock-up piston to be held against the torque converter cover. As this
takes Dlace, the mainshaft rotates at the same speed as the engine crankshatt. Together with hydraulic control, the TCM
optimizes the timing ol the lock-up mechanism.
The lock-up valves control the range of lock-up according to lock-up control solenoid valves A and B, and throttle valve B
When lock-up control solenoid valves A and B activate, modulator pressure changes. Lock-up control solenoid valves
A and B are mounted on the torque converter housing, and are controlled by the TCM.
(cont'd)
14-3
Description
(cont'd)
Gear Selection
The selector lever has seven posirions; E PARK, E REVERSE, N NEUTRAL, @ 1st through 4th positions. E 1st
through 3rd positions, Ql2nd gear and [] 1st gear.
Starting is possible only in @ and I Oosition through use ot a slide-type, neutral-safety switch.
Automatic Tlansaxle {A/T) Gear Position Indicatol
A/T gear pos;tion indicator in the instrumenl panel shows what gear has been selected without having look down at
the console.
Position Description
l3?]] PARK Front wheels locked; parking pawl engaged with parking gear on countershatt. All clutches
reteaseo,
[R] REVERSE Reverse; reverse selector engaged with countershalt reverse gear and 4th clutch locked.
N NEUTRAL All clurches released.
D+l DRIVE General driving; starts off in 'lst, shifts automatically to 2nd, 3rd, then 4th, depending on vehicle
('lst through 4th) speed and throttle position. Do'vnshifts through 3rd, 2nd and 1st on deceleration to stop.
The lock-up mechanism comes into operation in 2nd, 3rd and 4th when the transmission in lDtposrtron.
Dgi DRIVE For rapid acceleration at highway speeds and general driving; starts off in 1st. shifts automatical-(1st through 3rd) ly to 2nd then 3rd, depending on vehicle speed and throttle position. Downshifts through lower
gears on deceleration to stop. The lock-up mechanism comes into operation in 3rd.
El SECOND Driving in 2nd geari stays in 2nd gear, does not shift up and down.
For engine braking or better traction starting off on loose or slippery surfece.
L]l FIRST Driving in 1st gear; stays in lst gear, does not shilt up.
For engine braking.
14-4
Description
Clutches
The four speed automatic transmission uses hydraulically actuated clutches to engage or disengage the transmission gears.
When clutch pressure is introduced into the clutch drum, the clutch piston is applied. This presses the iriction discs and
steel plates together, locking them so they don't slip. Power is then transmitted through the engaged clutch pack tojts hub-mounted gear.
Likewise, when clutch pressure is bled from the clutch pack. the piston releases the friction discs and steel plates, and
they are {ree to slide past each other while disengaged. This allows the gear to spin independently on its shaft, transmit-
ting no power.
1st ClutchThe l st clutch engages/disengages 1st gear, and is located at the end of the mainshaft, just behind the right side cover.
The 1st clutch is supplied clutch pressure by its oil feed pipe within the mainshaft.
1st-hold clutchThe 1st-hold clutch engages/disengages 1st-hold or I Fosition, and is located at the center ol the sub-shaft. The 1st-
hold clutch is supplied clulch pressure by its oil feed pipe within the sub-shait.
2nd ClutchThe 2nd clutch engages/disengages 2nd gear, and is located at the center of the mainshaft. The 2nd clutch is joined
back-to-back to the 4th clutch. The 2nd clutch is supplied clutch pressure through the mainshaft by a circuit connected
to the regulator valve body.
3rd Clutch
The 3rd clutch engages/disengages 3rd gea.. and is located at the end oJ the countershaft, opposite the right side cover.
The 3rd clutch is supplied clutch pressure by its oil feed pipe within the countershaft,
4th clurch
The 4th clutch engages/disengages 4th gear. as well as reverse gear, and is located at the center of the mainshaft.
The 4th clutch is joined back-to-back to the 2nd clutch. The 4th clutch is supplied clutch pressure by its oil feed pipe
within the mainshalt.
One-way Clutch
The one-way clutch is posjtioned between the parking gear and 1st gear. with the parking gear splined to the counter-
shaft. The 1st gear provides the outer race, and the parking gear provides the inner race surface. The one-way clutch
locks up when power is transmitted from the mainshaft 1st gear to the countershaft lst ggel _The 1st clutch and gears remain engaged in the 1st. 2nd. 3rd, and 4th gear ranges in the @, E or E position.
However, the one-way clutch disengages when the 2nd. 3rd, or 4th clutches/gears are applied in the E, lD.l o, Eoosttton.
This is because the increased rotational speed of the gears on the countershaft over-ride the locking "speed range" of
the one-way clutch. Thereafter, the one-way clutch free-wheels with the lst clutch still engaged.
COUNTERSHAFT 1ST GEAR
FREE
:>
LOCKS
aF
NOTE:View trom right side cover side.
14-6
. Ascending Contlol
When the TCM determines that the vehicle is climbing a hill in @ position, the system extends the engagement area
of 3rd gear to prevent the transmission Irom frequenrly shitting between 3rd and 4th gears, so the vehicle can run smooth
and have more power when needed.
NOTE: Shift schedules between 3rd and 4th gear are stored in the TCM to enable the transmission to automatically
select the most suitable gear according to the magnitude of a gradient by Fuzzy logic.
. Descending Control
When the TCM determines that the vehicle is going down a hill in @ position. the shift-up speed from 3rd to 4th gear
when the throttle is closed becomes taster than the set speed for tlat road driving to widen the 3rd gear driving area.
This, in combination with engine brake from the deceleration lock-up, achieves smooth driving when the vehicle is
descending.
There are two ascending modes with different 3rd gear driving areas according to the magnitude of a gradient stored in
the TCM.
When the vehicle is in 4th gear, and you are decelerating on a gradual hill, or when you are applying the brakes on a
steep hill, the transmission will downshitt to 3rd gear. When you accelerate the transmission will then return to 4th gear.
F
0
. Deceleration Control
Vohicle SDood
When the vehicle goes around a corner, and needs to decelerate first and then accelerate, the TCM sets the data for
deceleration control to reduce the number of times the transmission shifts to obtain smooth driving. When the vehicle
is decelerating from speeds above 27 mph (43 km/h). the TCM shifts the transmission from 4th to 3rd earlier than normal
to cope with upcoming acceleration to maintain smooth driving.
NOTE:
Fuzzy Logic: Fuzzy logic is a from at artificial intelligence that lets computers respond to changing conditions much like
a human mind would.
14-21
E Position
As the engine turns, the oil pump also starts to operate. Automatic transmission fluid (ATF) is drawn from (99) and dis-
charged into (1 ). Then, ATF pressure is controlled by the regulator valve and becomes line pressure ( 1 ). The torque con-
verter inlet pressure (92) enters (94) of torque converter through the orifice and discharges into {90}.
The torque converter check valve prevents the torque converter pressure from rising'
Under this condition, the hydraulic pressure is not applied to the clutches.
NOTE:. When used, "left" or "right" indicates direction on the llowchart
. SOL-@: Shift Control Solenoid Valve A
' SOL{D:Shift Control Solenoid Valve B
. SOL@: Lock-up Control Solenoid Valve A
. SOL-@: Lock-up Control Solenoid Valve B
(cont'd)
14-29