SELVA MARINE Blue Whale 250 EFI, Service Manual

Page: 38 / 377

GEN
INFO
General information
1-33
6P23H11
Electronic throttle valve control system
In the Blue Wlale 250 engine, the electronic throttle valve control system converts the opening and
closing of the remote control lever accelerator to an electronic signal and the ECM controls the
throttle valves according to the operating condition of the accelerator opening.
Electronic throttle valve control
Electronic throttle valve operation
A cable transmits the operation of the remote control lever to the accelerator position sensor, which
converts the accelerator lever opening angle to an electronic signal. The ECM uses this signal to set
the target opening angle of the throttle valve. At the same time, the TPS detects the throttle valve
opening angle and checks the difference to that of the target opening angle. Then, the ECM sends
an electronic signal to the electronic throttle valve motor and performs feedback control of the differ-
ence of the target opening angle and throttle valve opening angle.
1
Remote control box
2
Accelerator position sensor
3
Accelerator lever
4
ECM
5
Electronic throttle valve assembly (TPS)
6
Electronic throttle valve motor
È
Throttle cable
É
Sensor signal
Description Control Engine condition
Setting of the target
throttle valve
opening Detects the accelerator sensor signal and
the ECM sets the target throttle valve open-
ing. Starting and normal oper-
ation.
Throttle valve
opening feedback Checks the difference between the signal
from the TPS and the target throttle valve
opening and performs feedback control on
the throttle valve opening. Starting and normal oper-
ation.
Engine idle speed Controls the throttle valve opening to stabi-
lize the engine speed at idle while control-
ling the intake air volume. Operation at engine idle
speed.
Limp home
processing
(electronic throttle
valve fail-safe) Fixes the throttle valve opening to the speci-
fied opening angle and controls the ignition
timing control according to the accelerator
position sensor opening angle. • The engine idle speed is
increased and stabilized.
• The engine speed is
fixed even if the acceler-
ator lever is opened.
S6P21121
1 2 5 4
È É É
3
6