Volvo TAD650VE, Руководство по ремонту

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Component description Group 30: Electrical system
18
Engine control unit, EMS 2
The engine control unit checks and controls the injec-
tors, to ensure that the correct volume of fuel is inject-
ed into each cylinder at the right time. It also controls
the high pressure pump via the proportional valve
(MPROP) to ensure that the system always has the
correct fuel pressure (rail pressure).
The control unit also calculates and adjusts the injec-
tion advance. Regulation is mainly done with the aid of
the engine speed sensor and the combined sensor for
boost pressure/boost temperature.
The EMS 2 system processor is located in the control
unit, protected from water and vibration.
The processor receives continuous information about:
• Engine speed
•
Throttle
• Oil pressure
• Boost pressure /temperature
• Fuel pressure (common rail pressure)
• Fuel alarm, “water in fuel”
• Camshaft position
• Coolant temperature
The information provides information about current op-
eration conditions and allows the processor to calculate
the correct fuel volume, monitor engine status etc.
Preheater with preheater relay
The preheater is located in the inlet manifold at the left
side of the engine. The preheat relay is located at the
engines left side beneath the preheater.