Page 36 of 2771
AT-24
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
“D3”, “23” and “13” Positions
*: Overrun clutch remains in engaged condition when throttle opening is less than 1/16.
SAT378J
•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: OD OFF (OD OFF indicator lamp is on) and throttle opening is less than specification*
2
3 and 13: Always engaged
Page 37 of 2771
A/T CONTROL SYSTEM
AT-25
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P “D
4” (OD) Position
SAT379J
•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 transaxle line and engine brake
can be obtained when decelerating.
Page 38 of 2771
AT-26
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
“R” Position
SAT380J
•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 transaxle line, engine brake can be obtained
when decelerating.
Page 39 of 2771

A/T CONTROL SYSTEM
AT-27
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
TCM FunctionINFOID:0000000001703163
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 sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
SAT381J
SWITCHES & SENSORS
⇒TCM
⇒ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Turbine revolution sensor (Power
train revolution sensor)
Vehicle speed sensor
Overdrive control switch signal
Stop lamp switch signalShift control
Line pressure control
Lock-up control
Overrun clutch control
Fail-safe control
Self-diagnosis
CONSULT-III communication
line controlShift solenoid valve A
Shift solenoid valve B
Overrun clutch solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
OD OFF indicator lamp
Page 40 of 2771

AT-28
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000001703164
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. For details, refer to LAN-6,
"System Description".
Input/Output Signal of TCMINFOID:0000000001703165
SCIA7112E
Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
functionSelf-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXX(*3) XX
Vehicle speed sensor·A/T
(Revolution sensor)XXXXX(*3) XX
Vehicle speed sensor·MTR (*1) X (*1) X (*1) X (*1) X X
Closed throttle position signal
(*5)(*2) X (*2) X X X (*4) X
Wide open throttle position signal
(*5)(*2) X (*2) X (*4) X
Turbine revolution sensor (Power
train revolution sensor)XXXXX
Engine speed signal X X X X
PNP switch XXXXX(*3) X(*4) X
Stop lamp switch signal
(*5)XX (*4) X
A/T fluid temperature sensors
(*5)XXXX XX
Overdrive control switch signal
(*5)XXXX (*4) X
TCM power supply voltage signal X X X X
Page 43 of 2771

A/T CONTROL SYSTEM
AT-31
< SERVICE INFORMATION >
D
E
F
G
H
I
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K
L
MA
B
AT
N
O
P
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 figure 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 ControlINFOID:0000000001703168
The torque converter clutch piston in the torque converter is locked to eliminate torque converter slip and 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 positions, 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.
TORQUE CONVERTER CLUTCH SOLENOID VALVE CONTROL
Gear position 1 2 3 4
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
SAT009J
OD ON OFF
Selector lever “D” position
Gear position D
4D3
Vehicle speed sensor More than set value
Accelerator pedal position signal Less than set opening
Closed throttle position signal OFF
A/T fluid temperature sensor More than 40°C (104°F)
Page 58 of 2771
AT-46
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
A/T Electrical Parts Location
INFOID:0000000001703180
1. OD OFF indicator lamp 2. Shift position indicator 3. Accelerator pedal position (APP)
sensor
4. Turbine revolution sensor (Power
train revolution sensor)5. PNP switch 6. Terminal body (Terminal cord as-
sembly connector)
BCIA0037E
Page 83 of 2771

TROUBLE DIAGNOSIS
AT-71
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
TCM Terminal and Reference ValueINFOID:0000000001703192
TCM HARNESS CONNECTOR TERMINAL LAYOUT
Terminals and Reference Values for TCM
TCM terminal data are reference values, measured between each terminal and ground.
OthersATF shoots out during
operation.
White smoke emitted
from exhaust pipe
during operation.ON vehicle 1. A/T fluid levelMA-22
OFF vehicle2. Reverse clutchAT- 2 7 9
3. High clutchAT- 2 8 4
4. Brake bandAT- 3 0 7
5. Forward clutchAT- 2 8 8
6. Overrun clutchAT- 2 8 8
7. Low & reverse brakeAT- 2 9 5
Unusual smell at A/T
fluid charging pipe.ON vehicle 1. A/T fluid levelMA-22
OFF vehicle2. Torque converterAT- 2 4 0
3. Oil pumpAT- 2 6 0
4. Reverse clutchAT- 2 7 9
5. High clutchAT- 2 8 4
6. Brake bandAT- 3 0 7
7. Forward clutchAT- 2 8 8
8. Overrun clutchAT- 2 8 8
9. Low & reverse brakeAT- 2 9 5
Items Symptom Condition Diagnostic item Reference page
WCIA0717E
Te r m i n a lWire
colorItem ConditionJudgement stan-
dard (Approx.)
1WLine pressure solenoid
valveWhen releasing accelerator pedal after
warming up engine.1.5 - 3.0 V
When depressing accelerator pedal ful-
ly after warming up engine.0 V
2PLine pressure solenoid
valve (with dropping re-
sistor)When releasing accelerator pedal after
warming up engine.4 - 14 V
When depressing accelerator pedal ful-
ly after warming up engine.0 V
3GRTorque converter clutch
solenoid valveWhen A/T performs lock-up. 8 - 15 V
When A/T does not perform lock-up. 0 V
5 L CAN H — —
6 P CAN L — —
10 R Power supplyWhen turning ignition switch to “ON”. Battery voltage
When turning ignition switch to “OFF”. 0 V