Kohler 26RCAL error codes
40 codes from the official Kohler manual (RCA/RCAL generator sets (TP-7092 9/23)), each with the manual page. For 25 of them the manual says to contact an authorized service dealer.
Applies to: Kohler 26RCAL.
| Code | What it means | What to do | Service | Manual |
|---|---|---|---|---|
| AC Sens Loss AC sensing lost | In Auto mode, generator output AC sensing is lost. Warning if no output is detected 1 second after crank disconnect; shutdown if voltage was present and then lost for 3 seconds. | Contact an authorized dealer for service. | dealer | p. 37 |
| ATS ComError ATS communication error | Warning displayed when the connection to the transfer switch interface board is lost. | Check the communication wiring between the transfer switch interface board and the generator set. | owner | p. 37 |
| ATS PhaseRot ATS phase rotation mismatch | Transfer switch phase rotation does not match, so the ATS will not transfer. | Correct the ATS connection. Refer to the ATS Installation manual, wiring diagrams, and labels on the transfer switch. | owner | p. 37 |
| Accy PwrOver Accessory Power Overload | An overcurrent fault (short circuit) on the accessory controller power output. | Contact an authorized dealer for service. | dealer | p. 37 |
| Advanced Diagnostic Advanced Diagnostic SD | Shutdown during the reduced speed portion of an exercise. The engine restarts, runs at full speed for 2 minutes, then stops and the controller returns to AUTO. Exercise schedule is unchanged. | If the generator set does not restart and return to AUTO, check for other faults that prevent generator set operation. | owner | p. 37 |
| Aux Input Auxiliary input | An optional customer-connected input is closed (digital input from optional PIM). | Check customer-supplied equipment. | owner | p. 37 |
| Batt Chg Flt Battery charger fault | Input to the PIM from an external battery charger (not the built-in charger) indicates a charger fault. | Check the external battery charger. | owner | p. 37 |
| Battery CrLo Battery voltage high | Engine starting battery voltage rises above 16 VDC for more than 10 seconds. Inhibited during the crank cycle; clears when voltage returns to an acceptable level. | Check the battery rating and condition. Check the battery charger. | owner | p. 37 |
| Low Oil Level or Oil Pressure | The oil level switch on the 26RCA indicates low oil level, or the LOP switch indicates low oil pressure for more than 5 seconds. Active 30 seconds after crank disconnect. | Check for lubrication system leaks. Check the oil level and add oil if low. Check the oil level or pressure switch and wiring. If the fault persists, do not run the generator set. Contact an authorized dealer for service. | dealer | p. 38 |
| Not in Auto | The generator set is not in Automatic (standby) mode, so remote start and stop commands from a transfer switch or remote switch are ignored. | Press AUTO to place the generator set in Automatic mode when appropriate. | owner | p. 38 |
| Over Crank | Three unsuccessful starting attempts have occurred. | Check the fuel supply, spark plug, and battery. Check for loose connections. Contact an authorized dealer for service. | dealer | p. 38 |
| Spd Sens Flt | The engine speed sensor has failed or the engine has stalled. | Contact an authorized dealer for service. | dealer | p. 38 |
| Volts L1-L2 High | Generator output voltage exceeds 120% of the system nominal voltage for more than 2 seconds. | Contact an authorized dealer for service. | dealer | p. 38 |
| Volts L1-L2 Low | Generator output voltage falls below 80% of the nominal system voltage for more than 10 seconds. | Reduce the load and restart the generator set. Check the enclosure thermostat and reset if tripped. Contact an authorized dealer for service. | dealer | p. 38 |
| BusDeadLive | The bus is measured dead when one generator should be supplying voltage to the bus (closed contactor). | Check that V9A and V9B are correctly connected to V9 of the paralleling protection harness. Contact an authorized dealer for service. | dealer | p. 39 |
| BusLiveDead | The bus is measured live when no generators are connected to it (both contactors open). | Check that V9A and V9B are correctly connected to V9 of the paralleling protection harness. Contact an authorized dealer for service. | dealer | p. 39 |
| CfgModelNum | The two generators intended to be paralleled have incompatible model numbers. | Verify the paralleled sets are the same kW model (two 14 kW, two 20 kW, or two 26 kW). Contact an authorized dealer for service. | dealer | p. 39 |
| CfgSysVolt | The system voltages of the two generators are not the same, so neither generator is allowed to start. | Check the configuration of both generators and the RBUS network wiring for intermittent connections. Contact an authorized dealer for service. | dealer | p. 39 |
| ChkngMeter | Status message: the generator is verifying that metering is connected and establishing connection direction after paralleling. | No action listed. Appears the first time the two generators are paralleled. Contact an authorized dealer for paralleling service if needed. | dealer | p. 39 |
| ConCheckFail | Failure to auto-discover APM connections. | Check that wires 9A and 9B are not crossed between the generators and are connected. Contact an authorized dealer for service. | dealer | p. 39 |
| ConChecking | Status message: APM connection auto-discovery is in progress; this generator started in RUN while the other is in OFF. | No action listed. Contact an authorized dealer for paralleling service if needed. | dealer | p. 39 |
| ConNotDeterm | APM connection auto-discovery is not complete; the generator does not know which contactor is connected to it. | Start each generator in RUN with the other in OFF to perform auto-discovery, per the APM instruction sheet. Contact an authorized dealer for service. | dealer | p. 39 |
| ContactorOk | Status message: auto-discovery of APM connections was successful. | No action listed. Contact an authorized dealer for paralleling service if needed. | dealer | p. 39 |
| Current A High | Over current warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| ErraticSig | Power metering signal is inconsistent with the system configuration and does not resolve when power direction is reversed. | Check the CT wiring for bad connections and check for excessive tension on the wires from the CT to the controller. Contact an authorized dealer for service. | dealer | p. 39 |
| Frequency High | Over frequency warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| Frequency Low | Under frequency warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| LossOfComAPM | The Automatic Paralleling Module was detected on RBUS but has stopped communicating. | Check the APM is plugged in, the primary controller is powered, and the battery connections are good. Check RBUS communication connections for intermittent wiring. Contact an authorized dealer for service. | dealer | p. 39 |
| Reactive Power Low | Loss of field warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| Real Power High | Over power warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| Real Power Low | Reverse power warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| Voltage L1-L2 High | Over voltage warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| Voltage L1-L2 Low | Under voltage warning while paralleled. Protective relay disconnects the contactor. Warning delay 10 seconds. | Press AUTO or OFF to clear. Pressing OFF will stop the generator set. | owner | p. 39 |
| LossOfComm2 | The primary controller lost communication with the secondary controller after previously detecting it. | Check RBUS connections, the secondary controller battery, and for intermittent RBUS connections. Contact an authorized dealer for service. | dealer | p. 40 |
| LossOfField | This generator has absorbed more than 25% reactive power for 20 seconds. | Have generator and bus voltage calibration checked on both generators. Contact an authorized dealer for service. | dealer | p. 40 |
| MeterUnknown | The generator does not know whether metering is connected or its connection orientation, so load cannot be shared accurately. | Complete system commissioning and startup per the APM instructions. Contact an authorized dealer for service. | dealer | p. 40 |
| MeteringOk | Status message: the metering is connected correctly and the power direction is consistent with expected direction. | No action listed. Contact an authorized dealer for paralleling service if needed. | dealer | p. 40 |
| NoCurrent | The generator applied load through the other generator but observed no current on the power sensing inputs. | Check that the CT is connected and that the output leads pass through the CT in the correct direction, per the APM instructions. Contact an authorized dealer for service. | dealer | p. 40 |
| SyncFailure | The generator has tried to synchronize for over 2 minutes without success, possibly due to hunting or frequent load changes. | Have advanced speed control settings adjusted if needed. Contact an authorized dealer for service. | dealer | p. 40 |
| Accy PwrOver Accy PwrOver Warning | The controller's internal circuit protection has activated. | Press OFF to reset. Contact an authorized Kohler dealer for service. | dealer | p. 82 |
ATS: automatic transfer switch.
Source: official Kohler manual, read 2026-10-26. "Owner" means the manual lists steps you can take; "dealer" means it directs you to authorized service. Fuel, gas and electrical work on generators is for qualified technicians; follow the manual's safety section.