Group 23 EMS 2 Design and function
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Control module EMS 2
The control module checks and controls the unit injec-
tors so that the correct amount of fuel is injected into
each cylinder. It calculates and sets the injection an-
gle. The control is primarily performed using the speed
sensors and the combined sensor for boost pressure/
charge air temperature.
The EMS 2 system processor is located in the control
unit, where it is protected from moisture and vibration.
The processor receives information continuously
about:
•
engine speed
•
camshaft position
•
charge air pressure
•
charge air temperature
•
coolant temperature
•
oil pressure
•
oil temperature
•
oil level
•
crankcase pressure
•
piston cooling pressure
•
water in fuel
•
fuel pressure
•
coolant level
•
air filter pressure
•
air filter temperature
Information from the sensors provides exact informa-
tion about current operation conditions and allows the
processor to calculate the correct fuel volume, check
engine status etc.
Control Interface Unit (CIU)
CIU is a control unit that handles all interactions with
the operator.
It communicates with the engine via two serial com-
munication buses. J1939 is used for control and moni-
toring of the engine. J1587 is used for diagnostics and
backup.
The CIU unit reads in the status of a number of
switches as well as the engine speed request and for-
wards them to the engine. It also controls the four an-
alog instruments and up to nine
warning lamps. By using the diagnostic button and a
diagnostic lamp, the driver can read off fault codes
from the system.