The Decision-Maker 550 is a generator-set controller. It is used on generator sets from Decision-Maker and Kohler, including the 1000 REOZM, 100ERESD, 100REOZJC and 100REOZJE.
Used across brands: Decision-Maker, Kohler
Also fitted to: Decision-Maker 550, Kohler Decision-Maker 550, Kohler G4-130 (150REZG), Kohler G4-131 (50REZG), Kohler G4-138 (100REZG), Kohler G4-140 (45REZG), Kohler G4-200 (80ERESD).
| Code | Meaning | Remedy |
|---|---|---|
| 32 | High Coolant Temperature | |
| 32A | Emergency Stop | Reset the emergency stop switch. |
| 40 | Pre High Coolant Temp. | |
| 41 | Pre Low Oil Pressure | Check and adjust oil level or replace oil pump. |
| 48 | Emergency Stop | |
| 62 | Low Battery Volts | |
| 63 | Low Fuel | Refuel the generator set. |
| Symptom | Cause | Remedy |
|---|---|---|
| Battery charger and/or block heater not functioning | Devices not connected to receptacle | Plug devices into respective receptacles |
| Cranks but does not start | Controller and Emergency Stop Switch | |
| Display is black | No/low battery charge | Recharge/replace battery |
| Display locks up | No/low battery charge | Recharge/replace battery |
| Display shows an EEPROM WRITE ERROR message | EEPROM fault caused by component failure, lightening strike, or voltage spike | Reinitialize the problem data block; Contact an Authorized Distributor/Dealer |
| Display shows an error message | Controller firmware or pushbutton/rotary selector dial entry error | Review the System Fault Shutdown Lamp With Digital Displays section |
| Display shows single segment | Low battery voltage | Recharge battery |
| Displays error message/locks up | Controller master control buttons inoperative | Replace the controller master control button circuit board. |
| Does not crank | Controller and Emergency Stop Switch | |
| Duplex circuit breaker(s) tripped or trips when reset | Circuit breaker overloaded | Reduce circuit load. Reset duplex circuit breaker(s). |
| Duplex receptacles have no power | Generator set not running | Power to duplex receptacles is from the generator set—not shore power. |
| Excessive or abnormal noise | Vibration excessive | Tighten loose components. |
| Exercise run time and/or event records inoperative | Controller clock not set | Reset time and date. |
| High fuel consumption | Compression weak | Check the compression. |
| Lacks power | Air cleaner clogged | Clean or replace the filter element. |
| Low oil pressure | Oil level low | Restore the oil level. Inspect the generator set for oil leaks. |
| Main circuit breaker(s) tripped or trips when reset | Circuit breaker overloaded | Reduce circuit load. Reset circuit breaker. |
| No or low output voltage | Voltage regulation inoperative | Replace the junction box sensing fuses. If the fuse blows again, troubleshoot the controller. |
| Output voltage ramps | Defective exciter winding | Troubleshoot alternator components |
| Output voltage unstable | Voltage regulation calibration incorrect | Readjust voltage regulation |
| Overheats | Governor inoperative | Adjust the governor. |
| Speed adjust does not function | Analog input A06 is supported with Doosan, GM, and Volvo engines only | Check calibration values |
| Starts hard | Controller fault | Troubleshoot the controller. |
| Stops suddenly | Engine overload | Reduce the electrical load. See the generator set spec sheet for wattage specifications. |
| Tow vehicle and trailer are unstable or noisy during braking | Tow vehicle brakes worn | Check brake fluid level. Add fluid as necessary. |
| Trailer is unstable or noisy during towing. | Tire(s) worn or damaged | Check tire condition. Repair or replace. |
| Unable to change voltage and current calibrations | Calibration not enabled | Enable calibration in Generator Metering section 2.6.3 Calibration Submenu |
| Unable to find volt select menu | Volt select not enabled | Enable volt select in SiteTech |
| User-supplied wiring between customer connection panel and load devices feels hot or has burning odor | Wiring undersized for application | Contact onsite electrician or rental distributor. |
| Voltage adjust does not function for paralleling applications | Analog input A07 description does not match Analog Volt Adjust | Change description to Analog Volt Adjust using Monitor III software or enable analog voltage adjust in Menu 11 |
| Voltage selector switch knob does not rotate. | Padlock installed on lockout feature | Contact onsite electrician or rental distributor. |
| Voltage selector switch position does not match load voltage. | Unit not set up for application | Contact onsite electrician or rental distributor. See Section 3, Electrical Connections and Requirements, for more information. |
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.