Kohler 6RFOY troubleshooting: 24 fault codes and symptom-cause-remedy entries from the manufacturer's own service documentation.
Kohler 6RFOY — full specs, parts & maintenance.
| Code | Meaning | Cause |
|---|---|---|
| BLOWN F1 FUSE (REMOTE ANNUNCIATOR-3 AMP) | Blown controller fuse F1 | DEFECTIVE DECISION DEFECTIVE MONITOR (IF EQUIPPED) REMOTE ANNUNCIATOR (IF EQUIPPED) DEFECTIVE REMAINING ACCESSORIES AUDIO-VISUAL CONNECTED TO TB1-42A ALARM (IF EQUIPPED) |
| BLOWN F2 FUSE (CONTROLLER-3 AMP) | Blown controller fuse F2 | BATTERY CONNECTIONS REVERSED SHORTED DC SUPPLY TO INDICATOR PANEL SHORTED CONTROLLER CIRCUIT BOARD |
| LOP | Low Oil Pressure (LOP) Shutdown | |
| HET | High Engine Temperature (HET) Shutdown | |
| LWL | Low Water Level (LWL) Shutdown | |
| 36 | High Engine Temperature | |
| 38 | Low Oil Pressure | |
| OC | Overcrank | |
| OS | Overspeed | |
| LOWT | Low Water Temperature |
| Symptom | Cause | Remedy |
|---|---|---|
| Unit will not crank | Weak or dead battery, Reversed or poor battery connections, Defective starter/starter solenoid, Defective start/stop switch (local or remote), Fuse blown in controller, Open in wiring, terminals, pin, circuit board, etc., Defective circuit board | Recharge or replace battery, Check connections, | Rebuild or replace Test function; replace if defective, Replace fuse; if fuse blows again, check circuit and components, Check continuity, Check circuit board operation |
| Crank but will not start | Out of fuel, Air cleaner clogged, Defective fuel solenoid, Defective fuel pump, Clogged fuel filter, Air in fuel system, Bad fuel mixture, Water, dirt in fuel system, Dirty, faulty fuel injectors | Replenish fuel supply, Clean or replace filter element, Test fuel solenoid, Test fuel pump Replace fuel filter Bleed air from system Replace fuel Drain, flush fuel system Clean/repair injectors |
| Engine knocks | Faulty fuel injector(s), Air in fuel injectors, Improper fuel, Incorrect fuel injection timing, Improper cylinder top clearance, Defective piston pin bearing, Defective crankshaft bearing or piston pin bearing, Improper valve clearance | Bleed air from system Use proper fuel; consult fuel supplier Clean/repair injectors Check clearance |
| Accidental starting | Disconnect battery cables before working on generator set (negative lead first and reconnect it last). Turn generator master switch to OFF position, disconnect power to battery charger, and remove battery cables (remove negative lead first and reconnect it last) to disable generator set before working on any equipment connected to generator. | |
| Blown controller fuse F3 | DEFECTIVE ENGINE ELECTRICAL DEFECTIVE OVERVOLTAGE BOARD DEFECTIVE PANEL LAMPS, ENGINE GAUGES COMPONENTS | |
| Engine will not crank | RUN POSITION PRESS LAMP TEST BUTTON; LAMPS LIGHT? IS BATTERY FULLY CHARGED? YES CHECK P3/P4 HARNESS/ CONNECTIONS CHARGE BATTERY AND ATTEMPT RESTART. IF ENGINE WILL NOT CRANK, CONNECTIONS O.K.? CONTINUE TROUBLESHOOTING SEQUENCE NO YES TO REPLACE P3/P4 oRouI NEE HARNESS BOARD;REPLACE | |
| Controller LED4 lit? | CONTROLLER LED2 AND LED3 LIT WITH MASTER EMERGENCY STOP SWITCH ACTIVATED? NO YES FAULT SHUTDOWN? CHECK ENGINE START CIRCUIT (P1 HARNESS, STARTER, SOLENOID, RESET EMERGENCY STOP [No] YES SWITCH (LOCAL AND REMOTE) CORRECT REPLACE CIRCUIT K BOARD CHECK FOR DC VOLTAGE AT FUSE F2 (3 AMP). SEE FIGURE 6-8. VOLTAGE AT FUSE INDICATES FUSE IS [no [ves ] GOOD. | |
| Engine cranks but will not start | LOW FUEL? YES REPLENISH FUEL SUPPLY LED3 LIT? NO YES CONTROLLER PANEL CHECK VOLTAGE AT F3 verre LIT? REPLACE CIRCUIT DEFECTIVE ENGINE STARTING CIRCUIT. BOARD CHECK FOR BATTERY VOLTAGE AND FUEL SOLENOID YES REPLACE CIRCUIT INSPECT FUSE BOARD HARNESS/CONNECTOR PINS HARNESS DEFECTIVE? [no [YES REPLACE CIRCUIT- REPAIR/REPLACE BOARD HARNESS | |
| Instrumentation not functioning properly | LOOSE INPUT OR INSTRUMENT LEAD CONNECTION AT AC FUSE TERMINAL BLOCK (TB3) OR INSTRUMENT? | SECURE CONNECTION AT AC FUSE TERMINAL BLOCK (TB3)? REPLACE FUSE; IF FUSE BLOWS AGAIN, REFER TO “FUSES” EARLIER IN THIS SECTION |
| High Fuel Consumption | Improper type fuel Clogged or dirty air cleaner element Engine overloaded Improper valve clearance Incorrect fuel injection timing Poor engine compression Fuel leakage | Use proper fuel Replace air cleaner element Reduce load Check for leakage at fuel tank, fuel lines, connections, etc. |
| No battery charging output | Loose or corroded connections Sulfated or worn-out battery Defective battery charging alternator Loose alternator belt | Retighten alternator belt Rebuild or replace alternator |
| No AC output | Circuit breaker open or defective (if equipped) Circuit breaker tripping due to overload on generator set No battery voltage to voltage regulator during cranking + terminals on regulator Blown voltage regulator fuse Open wiring, terminal, or pin in build-up circuit or voltage regulator circuit Brushes sticking in brush holder or broken brush springs Rotor slip rings dirty or corroded Defective rotor (open, shorted, or grounded windings) Defective stator (open, grounded, or shorted windings) Defective or misadjusted voltage regulator (PBIIIE only) Defective circuit board K4 relay (field flashing) (relay controller only) Defective K1 relay (field flashing) (5-Light Controller only) | Reset circuit breaker to ON position Check for voltage on line side Reduce load Check for DC voltage. at voltage regulator terminals Replace fuse; if fuse blows again, check voltage regulator and/or stator winding Check continuity Check brush position and condition Check slip ring condition Check voltage and continuity Check voltage and continuity Excite rotor separately and check for AC output Readjust voltage regulator Test/replace relay controller circuit board Test/replace K1 relay |
| Low output or excessive drop in voltage | Engine speed too low Generator overloaded Defective voltage regulator Voltage regulator improperly adjusted Loose voltage regulator connections (including stator sensing leads) | Check engine speed Reduce load Test/readjust voltage regulator Test/readjust voltage regulator Test and/or replace Test and/or replace |
| High generator output voltage | Engine speed too high Defective voltage regulator Voltage regulator improperly adjusted Loose voltage regulator connections (including stator sensing leads) | Check engine speed Test/readjust voltage regulator Check voltage regulator connections |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Weak or dead battery, Reversed or poor battery connections, Defective starter/starter solenoid, Defective start/stop switch (local or remote), Fuse blown in controller, Open in wiring, terminals, pin, circuit board, etc., Defective circuit board. See the table for the matching fixes.
Documented causes: Out of fuel, Air cleaner clogged, Defective fuel solenoid, Defective fuel pump, Clogged fuel filter, Air in fuel system, Bad fuel mixture, Water, dirt in fuel system, Dirty, faulty fuel injectors. See the table for the matching fixes.
Documented causes: Faulty fuel injector(s), Air in fuel injectors, Improper fuel, Incorrect fuel injection timing, Improper cylinder top clearance, Defective piston pin bearing, Defective crankshaft bearing or piston pin bearing, Improper valve clearance. See the table for the matching fixes.