Yanmar Engine Electrical Components; Can--Bus Communications - Toro Groundsmaster 4500-D Service Manual

Yanmar Engine Electrical Components

When servicing or troubleshooting the engine electrical
components, use the correct engine service manual and
troubleshooting manual. Also, the Yanmar SMART-
ASSIST--Direct electronic control diagnostics service
system is available to support the error diagnosis and
maintenance services of engine electrical control
devices.
CAN- -bus Communications
The Toro TEC controller(s), the Yanmar Engine Control-
ler and the InfoCenter Display used on the Ground-
smaster 4500--D and 4700--D communicate with each
other on a CAN--bus system. Using this system allows
the traction unit to fully integrate all the different electri-
cal components of the tractor and bring them together
as one. The CAN--bus system reduces the number of
electrical components and connections used on the ma-
chine and allows the number of wires in the wire harness
to be significantly reduced. The integration of electrical
functions also allows the InfoCenter Display to assist
with electrical system diagnostics.
Electrical System
CAN identifies the Controller Area Network that is used
between the controllers on the Groundsmaster. Two (2)
specially designed, twisted wires form the bus. These
wires provide the data pathways between the control-
lers (the TEC controllers and the Yanmar electronic con-
trol unit) and the InfoCenter Display used on the
machine. The engineering term for these wires are CAN
High and CAN Low. At the ends of the twisted pair of bus
wires are 120 ohm termination resistors. One of these
resistors is included in the wire harness and the second
is inside the engine ECU.
Each of the components that is controlled by the CAN--
bus link needs only four (4) wires to operate and commu-
nicate to the system: CAN High, CAN Low, B+ (power)
and ground. The CAN--bus needs the ignition switch ON
input for both the TEC and engine ECU to be activated.
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