HomeControllersDecision-Maker 3500

Decision-Maker 3500 Controller

The Decision-Maker 3500 is a generator-set controller. It is used on generator sets from Kohler, including the 100EFOZ, 100REOZJ4, 11EFKOZD and 120REOZT4.

112
Generator sets
Kohler
Brand
11–500 kW
Power range
4
Fuel types

Troubleshooting

18

Fault codes

CodeMeaningRemedy
32High Coolant Temperature
32AEmergency StopReset the emergency stop switch.
40Pre High Coolant Temp.
41Pre Low Oil PressureCheck and adjust oil level or replace oil pump.
48Emergency Stop
62Low Battery Volts
63Low FuelRefuel the generator set.

Symptoms & remedies

SymptomCauseRemedy
Accidental startingDisconnect the battery cables before working on the generator set. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery.
Canadian installations onlyFor standby service connect the output of the generator set to a suitably rated transfer switch in accordance with Canadian Electrical Code, Part 1.
Hot coolant and steamBefore removing the pressure cap, stop the generator set and allow it to cool. Then loosen the pressure cap to relieve pressure.
Hot engine and exhaust systemDo not work on the generator set until it cools.
Low Coolant Temperature (LCT) fault alarms occur even when a block heater is installed and properly functioning.The LCT sender was installed in the incorrect location on the unit. In this case, the sender was installed in a tee fitting on the return line from the engine block to the block heater. The correct LCT location is in the thermostat housing.
Osed moving partsKeep hands, feet, hair, clothing, and test leads away from the belts and pulleys when the generator set is running. Replace guards, screens, and covers before operating the generator set.
Parallel OperationThis product includes features intended to support operation in parallel with the utility grid, but these features have not been evaluated for compliance with specific utility interconnection protection standards or requirements.
Servicing the exhaust system. Hot partsDo not touch hot engine parts.
The LCT sender/switch at the tee of the return line between the engine block and block heater has two terminals, indicating it is an incorrect sender/switch.Order LCT sender GM39458. Go to step 1.3.
Unbalanced weightDo not use lifting eyes. Lift the generator set using lifting bars inserted through the lifting holes on the skid.
Voltage reconnectionAffix a notice to the generator set after reconnecting the set to a voltage different from the voltage on the nameplate. Order voltage reconnection decal 246242 from an authorized service distributor/dealer.

Fault codes and symptom→remedy steps extracted from this controller’s service/owner documentation; verify against the official manual before servicing. Aggregated from the service documentation of generator sets built on this controller.