The Decision-Maker 3000 is a generator-set controller. It is used on generator sets from General Motors and Kohler, including the GZ25, 100ERESD, 100ERESD-QS and 100ERESD-QS1.
Used across brands: General Motors, Kohler
Also fitted to: Kohler 25/30REZG, Kohler 80/100REZGC, Kohler G4-200 (80ERESD), Kohler Not explicitly stated in the document.
| 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. |
| F4 | Aux. winding fuse F4 blown (lead 55) | Replace blown fuse; If fuse blows again, check stator. |
| 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 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. |
| Emits black or gray smoke | Air intake restriction | Check air cleaner and intake. |
| Engine knocks | Excessive load | Reduce load. |
| Excessive or abnormal noise | Vibration excessive | Tighten loose components. |
| Generator set cranks but does not start | No fuel | Check the fuel supply. |
| Generator set does not crank | Weak or dead battery | Recharge or replace battery; Check battery charger connections and operation, if equipped. |
| Generator set is noisy | Exhaust system leaks | Check and replace as necessary. |
| Generator set lacks power | Air intake restriction, inadequate cooling | Inspect air intakes and exhaust for obstructions; Check the air cleaner. |
| Generator set operates erratically | Air cleaner clogged | Replace element. |
| Generator set overheats | Inadequate cooling | Inspect cooling system for obstructions. |
| Generator set starts but shuts down | Fault shutdown | Check for a fault shutdown message on the controller display; Correct the fault and then reset the controller. |
| Generator set starts hard | Low battery voltage | Check battery voltage; Check battery charger connections and operation, if equipped. |
| Generator set stops suddenly | Fault shutdown | Check for a fault shutdown message on the controller display; Correct the fault and then reset the controller. |
| High fuel consumption | Compression weak | Check the compression. |
| High generator output voltage | Incorrect controller voltage settings | Check and adjust the controller voltage settings. |
| High oil consumption | External leakage/defective gaskets | Replace gaskets. |
| Lacks power | Air cleaner clogged | Clean or replace the filter element. |
| Light flicker | Voltage stability (gain) setting | Check and adjust the voltage stability (gain) setting; Test/adjust voltage regulator. |
| 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. | |
| Low oil pressure | Oil level low | Restore the oil level. Inspect the generator set for oil leaks. |
| Low output or excessive drop in voltage | Generator overloaded | Reduce load. |
| 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. |
| No output voltage | AC output circuit breaker open | Check for AC voltage on the generator side of the circuit breaker; If there is AC voltage on the generator side of the breaker, then a problem in the load circuits is causing the line circuit breaker to trip; Check for and correct short circuits or overloading on the load side before resetting the circuit breaker. |
| 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. |
| Starts hard | Controller fault | Troubleshoot the controller. |
| Stops suddenly | Engine overload | Reduce the electrical load. See the generator set spec sheet for wattage specifications. |
| 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. | |
| 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 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.