Electronic Control System (A340F) - Toyota Hilux Surf 1993 Owner's Manual

ELECTRONIC CONTROL SYSTEM
The electronic control system, which controls the shift points and the operation of the lock–up clutch, is
composed of the following three parts:
1. Sensors
These sensors sense the vehicle speed, throttle opening and other conditions and send these data
to the ECM in the form of electrical signals.
2. ECM
The ECM determines the shift and lock–up timing based upon the signals from sensors, and con–
trols the solenoid valves of the hydraulic control unit accordingly.
3. Actuators
These are three solenoid valves that control hydraulic pressure acting on the hydraulic valves to
control shifting and lock–up timing.
SENSORS
DRIVING PATTERN
SELECTOR
PARK/NEUTRAL
POSITION SWITCH
THROTTLE POSITION
SENSOR
VEHICLE SPEED
SENSOR
BRAKE LIGHT SWITCH
O/D MAIN SWITCH
CRUISE CONTROL
ECU
ENGINE COOLANT
TEM–
PERATURE SENSOR
AUTOMATIC TRANSMISSION
Control of shift
timing
Control of lock–
up timing
Self–diagnostic
system
Back–up system
– Operation
ECM
AT–171
ACTUATORS
NO. 1
SOLENOID VALVE
NO.2
SOLENOID VALVE
LOCK–UP
SOLENOID VALVE
O/D OFF
INDICATOR LIGHT