Case CX130 - Page 175

ELECTRIC CIRCUIT
5 - 32
CASE TRAINING CENTER
AUGUST 2000
3) Checking the emergency mode
1. The engine electronic control box stops the engine
by cutting off the fuel injection if an assistance error
is detected at the electronic acceleration regulator
during operation or when starting the engine.
2. After stopping the engine due to a regulator
assistance error, the engine can be re-started in
emergency mode (IN3 = ON = GND).
3. When operating in emergency mode, the engine
electronic control box only checks the position of the
rack against the engine speed obtained by the engine
speed detector. Therefore normal engine
performance cannot be obtained, since the engine
emergency mode has taken over.
4) Timing diagram
1a. Normal
1b. Off
1c. Emergency mode
5) Engine control when the emergency
mode has taken over
The engine electronic control box determines the
target engine speed from the position of the engine
throttle control.
The engine electronic control box checks the position
of the electronic acceleration rack by the difference
between the real engine speed obtained by a signal
from a speed detector incorporated in the electronic
acceleration (or by the engine speed detector located
in the engine bell-housing) and the target speed.
In emergency mode, the engine speed is controlled
only by the engine throttle control. Control by the
engine throttle control is different from control under
normal conditions.
1d. Off
1e. Emergency mode
ST
ON
OFF
1a 1b 1c 1d 1e
10 sec
24 V
0 V
5 V
0 V
ON
OFF
ON
OFF
5 V
0 V
Supply
Emergency mode
Motor status
Starter motor
switch
OUT (IN4)
emergency mode
Regulator
assistance error
(IN3)
Engine control
mode
0 100
900
1600
Engine throttle control (%)
Engine
speed
(rpm)