Group 23 EMS 2 Design and function
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
charge air pressure
charge air temperature
piston cooling pressure
water in fuel
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
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
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.