Service Manual

Groundsmaster 4500−D/4700−D Page 3 − 5 Yanmar Diesel Engine
Engine Electronic Control Unit (ECU)
The Yanmar engine that powers your Groundsmaster
uses an electronic control unit (ECU) for engine man-
agement and also to communicate with the machine
TEC controllers and the operator Info Center display on
the machine. All wire harness electrical connectors
should be plugged into the ECU before the machine igni-
tion switch is moved from the OFF position to either the
ON or START position.
The engine electrical components (e.g. ECU, fuel inject-
ors, EGR, exhaust DPF) are identified and matched in
the engine ECU program. If engine electrical compon-
ents are replaced on the engine, the Yanmar electronic
tool must be used to update the ECU program which will
ensure correct engine operation.
If the engine ECU identifies that an engine problem ex-
ists, the engine speed may be reduced or the engine
might stop. The Yanmar electronic tool and
troubleshooting manual should be used to provide as-
sistance in identifying the cause of the problem and the
repairs that are necessary. Contact your Toro distributor
for assistance in Yanmar engine troubleshooting.
IMPORTANT: Do not plug or unplug the engine ECU
for a period of thirty (30) seconds after the machine
key switch is turned OFF. The ECU may remain ener-
gized even though the ignition switch is OFF.
If the engine ECU is to be disconnected for any reason,
make sure that the ignition switch is in the OFF position
with the key removed before disconnecting the engine
ECU. Also, to prevent possible ECU damage when
welding on the machine, disconnect and remove the en-
gine ECU from the machine before welding.
Figure 1
1. Engine (models 30873 and 30874)
2. Engine ECU
1
2
Figure 2
1
2
1. Engine (models 30881 and 30882)
2. Engine ECU
Yanmar
Diesel Engine