Hitachi ZW180 Technical Manual page 115

Engine Warning Indicator and Stop Indicator
Control
Purpose: To light the engine warning indicator and
stop indicator on monitor unit in order to
inform the engine serious failure detected
by ECM to the operator.
Operation:
1. When detecting the engine serious failure, ECM
grounds terminal #43. Therefore, terminals 2-21
and 2-22 of the monitor unit are grounded.
2. When terminals 2-21 and 2-22 of the monitor unit
are grounded, the monitor unit lights the engine
warning indicator and stop indicator.
Stop Indicator
Engine Warning
Indicator
SYSTEM / ECM System
Monitor
Unit
Diode B
2-22
2-21
3. When the engine returns to normal conditions,
ECM deactivates the ground connection to
terminal #43. Therefore, terminals 2-21 and 2-22
of the monitor unit are disconnected form the
engine.
4. When terminals 2-21 and 2-22 of the monitor unit
are disconnected form the engine, the monitor
unit turns off the engine warning indicator and
stop indicator.
NOTE: As priority is given to lighting the stop
indicator, the service indicator does not
light.
T2-2-9
ECM
43
T4GD-02-02-007