Kohler 20RES troubleshooting: 30 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Kohler 20RES — full specs, parts & maintenance.
| Code | Meaning |
|---|---|
| LossOfComm2 | Communication Lost with Secondary Controller |
| Symptom | Cause | Remedy |
|---|---|---|
| Battery short circuits | Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. | |
| Bodily injury and/or equipment damage | Battery short circuits | Disconnect the battery before generator set installation or maintenance. Remove all jewelry before servicing the equipment. Use tools with insulated handles. Remove the negative (--) lead first when disconnecting the battery. Reconnect the negative (--) lead last when reconnecting the battery. Never connect the negative (--) battery cable to the positive (+) connection terminal of the starter solenoid. Do not test the battery condition by shorting the terminals together. |
| Controller display backlight is off. | Backlight turns off after about 1 minute with no activity. Backlight will turn on when a button is pressed or the generator set starts. | |
| Controller display is off. | Low or no battery voltage. | Check connections. Check generator set battery. See Figure 5-5. |
| The generator set does not crank. | Battery weak or dead. | Recharge or replace the battery. |
| Fault shutdown. | Check the controller display for fault messages. See Section 2.5. Correct the fault condition and reset the controller. | |
| Generator set in the OFF mode. | Press the RUN button to start the engine or press AUTO to allow remote starting. | |
| Generator thermostat tripped. | Check for obstructed air inlets and outlets. Reset the thermostat. See Section 5.5. | |
| The generator set cranks but does not start, starts hard, lacks power, or operates erratically. | Air cleaner clogged. | Clean and/or replace the air cleaner. |
| Low oil pressure shutdown. | Check for oil leaks. Check the oil level and add oil if necessary. | |
| Fuel pressure insufficient. | Check the fuel supply and valves. | |
| Engine malfunction. | Contact an authorized distributor/dealer. | |
| No AC output. | Line circuit breaker in the OFF position. | Place the circuit breaker in the ON position. |
| Auxiliary winding circuit breaker tripped. | Reset the circuit breaker (located in controller’s service access area). Contact an authorized distributor/dealer for service if breaker trips repeatedly. | |
| Low output or excessive drop in voltage. | Generator set overloaded. | Reduce the load. |
| Generator set stops suddenly. | Low oil pressure shutdown. | Check for oil leaks. Check the oil level and add oil if necessary. |
| No fuel. | Check fuel valves and fuel supply. | |
| Overcrank shutdown. | Reset the controller. If the overcrank fault occurs again, contact an authorized distributor/dealer. | |
| Remote stop command received from a remote switch, ATS, or OnCuerPlus. | Check the remote switch position. Check OnCuerPlus. | |
| Accy PwrOver Warning or MainPwrOverL Shutdown | Internal circuit protection is activated. | Press OFF to reset. Contact an authorized Kohler distributor/dealer for service. |
| Generator set circuit breaker trips repeatedly | Contact an authorized distributor/dealer for service. | |
| Fault messages displayed on the controller | Identify and correct the cause of the fault condition. Then reset the controller after a fault shutdown. See Section 2.5.4. | |
| Generator set accidentally starts | Disconnect 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. | |
| Hot engine and exhaust system | Do not work on the generator set until it cools. | |
| Battery acid splashes in the eyes | Immediately flush the affected area for 15 minutes with large quantities of clean water. Seek immediate medical aid. | |
| Battery acid on skin | Flush the affected area for 15 minutes with large quantities of clean water and seek medical aid if necessary. | |
| Battery acid cleanup | Add 500 g (1 lb.) of bicarbonate of soda to a container with 4 L (1 gal.) of water and mix the neutralizing solution. Pour the neutralizing solution on the spilled battery acid until all evidence of a chemical reaction has ceased. Flush the resulting liquid with water and dry the area. | |
| Line circuit breaker tripping because of overload. | Reduce the load on the generator set. | |
| Line circuit breaker tripping because of short circuit. | Contact an authorized distributor/dealer for service. |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Battery short circuits. See the table for the matching fixes.
Documented causes: Backlight turns off after about 1 minute with no activity. Backlight will turn on when a button is pressed or the generator set starts.. See the table for the matching fixes.
Documented causes: Low or no battery voltage.. See the table for the matching fixes.