Volvo Penta TAD941GE Operator's Manual page 5

Presentation
EMS (Engine Management System) is an electronic system with CAN communication (Controller Area Network)
for diesel engine control. The system was developed by Volvo Penta and includes fuel control and diagnostic
function.
Input signals
The control unit receives input signals about engine
operating conditions, etc. from the following compo-
nents:
- coolant temperature sensor
- charge air pressure and charge air 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
Diagnostics function
The purpose of the diagnostic function is to detect and
locate any malfunctions in the EMS system, to protect
the engine and to ensure operation in the event of
serious malfunction.
If a malfunction is detected, it is announced by warn-
ing lamps, a flashing diagnostic lamp or in plain lan-
guage on the instrument panel, depending on the
equipment used. If a fault code is provided as a flash-
ing code or in plain language, it 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 the application).
Once again, a fault code is set for guidance in any
fault tracing.
10
EMS (Engine Management
System)
Output signals
The control module uses input signals to control the
following components:
- unit injectors
- starter motor
- main relay
- pre-heating relay
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.
47702660 03-2013 © AB VOLVO PENTA