SDMO RENTAL POWER R550C2 User And Maintenance Manual page 140

Presentation
EMS (Engine Management System) is an electronic system with CAN communication (Controller Area Network)
for diesel engine control. The system has been developed by Volvo Penta and includes fuel control and diagnostic
function.
Input signals
The control module receives input signals about the
engines operating conditions and other things from
the following components:
- coolant temperature sensor
- charge pressure/charge temperature sensor
- crankcase pressure sensor
- position sensor, camshaft
- speed sensor, flywheel
- coolant level sensor
- oil level and temperature sensor
- oil pressure sensor
- fuel pressure sensor
- water in fuel indicator
- exhaust temperature sensor (TWD1643GE)
Diagnostic function
The task of the diagnostic function is to discover and
localize any malfunctions in the EMS system, to pro-
tect the engine and to ensure operation in the event
of serious malfunction.
If a malfunction is discovered, this is announced by
warning lamps, a flashing diagnostic lamp or in plain
language on the instrument panel, depending on the
equipment used. If a fault code is obtained as a flash-
ing code or in plain language, this is used for guidance
in any fault tracing. Fault codes can also be read by
Volvo's VODIA tool at authorized Volvo Penta work-
shops.
If there is a serious malfunction, the engine will be
shut down altogether, or the control unit will reduce
the power delivered (depending on application). Once
again, a fault code is set for guidance in any fault trac-
ing.
10
EMS (Engine Management
System)
Output signals
Based on the input signals the control module controls
the following components:
- unit injectors
- starter motor
- main relay
- pre-heating relay
- wastegate (TWD1643GE, TAD1650VE)
- cold start valve (TWD1643GE)
- valve mechanism, internal EGR (TAD1650VE,
TAD1650/51GE)
Information from the sensors provides exact informa-
tion about current operation conditions and allows the
processor in the control unit to calculate the correct
fuel injection volume and timing, check engine status
etc.
Fuel control
The engine fuel requirement is analyzed up to 100
times per second. The amount of fuel injected into the
engine and the injection advance are fully electroni-
cally controlled, via fuel valves in the unit injectors.
This means that the engine always receives the cor-
rect volume of fuel in all operating conditions, which
offers lower fuel consumption, minimal exhaust emis-
sions etc.
138/298
7748681 12-2011