Kohler is a well-known company that makes power production systems, such as generators for homes and businesses. Kohler generators have powerful control systems that can keep an eye on how well the generator is working and spot any problems. These problems are shown by specific fault codes that help techs figure out what’s wrong and fix it faster.
Please keep in mind that Kohler generator fault codes can be different based on the model and type of generator. Kohler may also update its generators and their fault code systems from time to time, so it’s important to check the user manual or technical paperwork for the generator in question to get the most up-to-date information.
Kohler Generator Fault Code List
Engine
- 10 | Engine Oil Pressure Low | Low oil level, faulty oil pressure sensor, faulty oil pump
- 11 | Engine Oil Pressure High | Faulty oil pressure sensor
- 12 | Engine Coolant Temperature High | Low coolant level, faulty coolant sensor, faulty thermostat
- 13 | Engine Coolant Temperature Low | Faulty coolant sensor
- 14 | Engine Overspeed Shutdown | Engine speed too high, faulty engine speed sensor
- 15 | Engine Misfire | Faulty spark plugs, faulty ignition coils, faulty injectors, low fuel pressure
- 16 | Engine Crankshaft Position Sensor Fault | Faulty crankshaft position sensor, faulty wiring
- 17 | Engine Camshaft Position Sensor Fault | Faulty camshaft position sensor, faulty wiring
- 18 | Engine Knock Sensor Fault | Faulty knock sensor, faulty wiring
Exhaust System
- 20 | Catalyst Temperature High | Faulty catalyst, faulty exhaust gas temperature sensor
- 21 | Catalyst Efficiency Below Threshold | Faulty catalyst, faulty exhaust gas temperature sensor
- 22 | Exhaust Gas Recirculation (EGR) Fault | Faulty EGR valve, faulty EGR solenoid, faulty EGR cooler
Fuel System
- 30 | Fuel Pressure Low | Faulty fuel pressure regulator, faulty fuel pump, faulty fuel filter
- 31 | Fuel Pressure High | Faulty fuel pressure regulator
- 32 | Fuel Injector Fault | Faulty fuel injector, faulty injector wiring
Starting System
- 40 | Starter Solenoid Fault | Faulty starter solenoid, faulty starter wiring
- 41 | Starter Motor Fault | Faulty starter motor, faulty starter wiring
Generator
- 50 | Generator Overvoltage Shutdown | Faulty voltage regulator, faulty generator
- 51 | Generator Undervoltage Shutdown | Faulty voltage regulator, low fuel level
- 52 | Generator Overload Shutdown | High load, faulty generator
- 53 | Generator Phase Fault | Faulty generator
Other
- 60 | Control Board Fault | Faulty control board
- 61 | Communication Fault | Faulty communication between the control board and other components
| Code | Warning/ shutdown | Condition | Check |
| AC Sens Loss | W (1 sec.) SD (3 sec.) | AC sensing lost. In Auto mode, generator output AC sensing is lost. Detection begins 10 seconds after the crank disconnect | Contact an authorized distributor/dealer for service |
| Accy PwrOver W Warning | W | Accessory Power Overload. An over-current fault (short circuit) on the accessory controller power output | Contact an authorized distributor/dealer for service |
| Alt Protect | SD | A high generator current has been detected. The generator set shuts down to protect the alternator from damage caused by overheating the windings (10RESV and 12RESV only) | Reduce the load |
| ATS ComError | W | ATS communication error. The warning is displayed if the ATS interface connection is lost. See Section 2.5.3 | Check communication wiring between the transfer switch interface board and generator set |
| ATS PhaseRot | W | ATS phase rotation mismatch. Transfer switch phase rotation does not match, ATS will not transfer. | Correct the ATS connection. Refer to the ATS Installation manual, wiring diagrams, and labels on the transfer switch |
| Aux Input | SD | Auxiliary input. An optional customer-connected input is closed. (Digital input from optional PIM.) | Check customer-supplied equipment |
| Batt Chg Flt | W | Battery charger fault. Input to PIM from an external battery charger (not the built-in battery charger) | Check the external battery charger |
| Battery High | W | Engine starting battery voltage rises above 16 VDC for more than 10 seconds. Inhibited during the engine crank cycle. Clears when the battery voltage returns to an acceptable level | Check the battery rating and condition. Check the battery charger operation. |
| Battery Low | W | Engine starting battery voltage falls below 12.5 VDC for more than 90 seconds when the engine is not running. Not operative during the engine crank cycle. Clears when the battery voltage returns to an acceptable level | Check the battery rating and condition. Check the battery charger operation. Charge or replace the battery |
| Battery CrLo Warning | W | Engine starting battery voltage falls below 11 Volts for more than 10 seconds. Inhibited during the engine crank cycle. Clears when the battery voltage returns to an acceptable level. | Check the battery rating and condition. Check the battery charger operation. Charge or replace the battery |
| Eng Speed High | SD | Engine speed exceeds 115% of the normal running speed for more than 0.3 seconds. | Contact an authorized distributor/dealer for service |
| Eng Speed Low | SD | Engine speed drops below 85% of the normal running speed for more than 3 seconds | Reduce the load. Contact an authorized distributor/dealer for service. |
| Exer Not Sch | W | Exercise not scheduled. No exercise is scheduled on the controller. | See Section 3.6 or 4.5 for instructions to set the exerciser |
| Frequency High | SD | Governed frequency exceeds 110% of the system’s frequency setpoint for more than 10 seconds. Function becomes active 10 seconds after engine start (10 seconds inhibit) | Contact an authorized distributor/dealer for service |
| Frequency Low | SD | Governed frequency falls below 90% of the system frequency setting for more than 10 seconds, or 1 Hz below the system frequency setting for more than 60 seconds. Function becomes active 10 seconds after engine start (10-second inhibit). | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service |
| Lo Crank Vlt | W | Low cranking voltage. Battery voltage falls below 8 VDC for more than 6 seconds while the starter is engaged. | Charge or replace the battery |
| MainPwrOverL | SD | Main power overload. An over-current fault on the 70 controller power output (short circuit) | Contact an authorized distributor/dealer for service. Check for the short-run relay. Check wiring for short circuits |
| Not in Auto | W | The generator set is not in Automatic (standby) mode. Remote start and stop commands from a transfer switch or remote switch will be ignored | Press AUTO to place the generator set in Automatic mode, when appropriate |
| Oil Pres Low | SD | The LOP switch indicates low oil pressure for more than 5 seconds. Function becomes active 30 seconds after crank disconnect (30 second inhibit). Note: The low oil pressure shutdown does not protect against low oil levels. Check the engine oil level regularly as recommended in Section 5 | Check for leaks in the lubrication system. Check the oil level and add oil if the level is low. Check the oil pressure switch and wiring |
| Over Crank | SD | Three unsuccessful starting attempts | Check the fuel supply, spark plug, and battery. Reset the thermostat. Check for loose connections. Contact an authorized distributor/dealer for service |
| Spd Sens Flt | SD | The engine speed sensor has failed or the engine stalled | Contact an authorized distributor/dealer for service |
| Total Power High | SD | The measured load is greater than 102% of the generator set power rating for more than 1 minute (10RESV and 12RESV only). | Reduce the load |
| Volts L1-L2 High | SD | The generator voltage is high. Output voltage exceeds 120% of the system nominal voltage for more than 2 seconds | Contact an authorized distributor/dealer for service |
| Volts L1-L2 Low | SD | Generator voltage low. Output voltage falls below 80% of the nominal system voltage for more than 10 seconds | Reduce the load and restart the generator set. Contact an authorized distributor/dealer for service. |
If you see any of these codes on your Kohler generator, it is important to have it checked by a qualified technician. The code may indicate a problem with the generator that could lead to further damage if it is not repaired.
Here are some additional tips to prevent Kohler generator fault codes:
- Maintain your generator regularly: This includes changing the oil and filter, checking the coolant level, and inspecting the belts and hoses.
- Operate your generator within its limits: Do not overload the generator or run it for extended periods of time at high loads.
- Store your generator properly: When not in use, store your generator in a dry, cool place.
By following these tips, you can help to prevent Kohler generator fault codes and keep your generator running properly.