The Electronic Governor is a generator-set controller. It is used on generator sets from Cummins/Onan, Generac, General Electric / MQ Power, Kohler, Kubota, SDMO and Weichai, including the 5.5 HGJAE-2131, 5.5 HGJAE-2135, 5.5 HGJAE-2136 and 5.5 HGJAE-2144.
Used across brands: Cummins/Onan, Generac, General Electric / MQ Power, Kohler, Kubota, SDMO, Weichai
Also fitted to: Cummins/Onan DF, Generac 005818-1.
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| *4 | Green RUN lamp lights following engine start-up. | 7. Indicates all engine systems are normal. No corrective action required. | |
| 10 | LO FUEL lamp lights. Engine shuts down and LO OIL PRES lamp lights. | 10. Indicates engine has run out of fuel. Check fuel level and replenish as required. | |
| 11 | LO ENG TEMP lamp lights. Set is in standby mode but is not operating. | (Lamp lights when engine coolant temperature is 70°F (21°C) or lower. Since the lamp goes out after the engine warms up, there should be no cause for alarm even during initial generator set operation.) Indicates engine coolant heater is not operating or is not circulating coolant. Check for the following conditions: a. Coolant heater not connected to power supply. Check for blown fuse or disconnected heater cord and correct as required. b. Check for low coolant level and replenish if required. Look for possible coolant leakage points and repair as required. c. Contact an Onan Dealer or Distributor if none of the above. | |
| 2 | PRE HI ENGINE TEMP lamp lights. Engine continues to operate. | 2. Indicates engine has begun to overheat and engine temperature has risen to approximately 205°F (97°C). If generator is powering non-critical and critical loads and cannot be shutdown, use the following: a. Reduce load if possible by turning off non-critical loads. b. Check air inlets and outlets and remove any obstructions to airflow. c. Open doors or windows in generator area to increase ventilation. If engine can be stopped, follow procedure in step 3. | |
| 3 | HI ENG TEMP lamp lights. Engine shuts down. | 3. Indicates engine has overheated (engine temperature has risen above 215°F/102°C) or coolant level is low (sets with coolant level sensor). Allow engine to cool down completely before proceeding with the following checks: a. Check coolant level and replenish if low. Look for possible coolant leakage points and repair if necessary. b. Check for obstructions to cooling airflow and correct as necessary. c. Check for a slipping fan belt and tighten if loose. d, Reset control and restart after locating and correcting problem. Contact an Onan Dealer or Distributor if none of the above. | |
| 4 | PRE LO OIL PRES lamp lights. Engine continues to operate. | 4. Indicates engine oil pressure has dropped to 20 psi (138 kPa). If generator is powering critical loads and cannot be shut down, wait until next shutdown period and then follow step 5 procedure. If engine can be stopped, follow procedures in step 5. | |
| 5 | LO OIL PRES lamp lights. Engine shuts down. | 5. Indicates engine oil pressure has dropped to 14 psi (97 kPa). Check oil level, lines and filters. If oil system is okay but oil level is low, replenish. Reset control and restart. Contact an Onan Dealer or Distributor if oil pressure is not in the range of 50 to 70 psi (345 to 483 kPa). | |
| 6 | OVERCRANK lamp lights and engine stops cranking. | 6. Indicates possible fuel system problem. a. Check for empty fuel tank, fuel leaks, or plugged fuel lines and correct as required. b. Check for dirty fuel filter and replace if necessary (see MAINTENANCE section). c. Check for dirty or plugged air filter and replace if necessary (see MAINTENANCE section). d. Refer to Step 5. e. Reset the control and restart after correcting the problem. Contact an Onan Dealer or Distributor for service if none of the above. | |
| 7 | Engine runs and then shuts down, OVERSPEED lamp lights. | 7. Indicates engine has exceeded normal operating speed. Contact an Onan Dealer or Distributor for service. | |
| 72 | Overspeed | ||
| 8 | SWITCH OFF lamp flashes. | Position which will prevent automatic starting if an automatic transfer switch is used. Move the Run/Stop/Remote switch to the Remote position for automatic starting. | |
| 9 | LO FUEL lamp lights. Engine continues to run. | 9. Indicates diesel fuel supply is running low. Check fuel supply and replenish as required. | |
| A11-4 | Overspeed | Check engine manufacturer's manual for troubleshooting guide | |
| A11-5 | Overcrank | Check loss of fuel or ignition failure | |
| CB1 | Circuit Breaker CB1 | ||
| CB21 | Exciter Circuit Breaker | Are the rotating diodes CR1 through CR6 on the exciter rotor OK? Is the exciter stator winding OK? Is the generator main field winding OK? is the exciter rotor winding OK? Replace CB21 circuit breaker. Test CR21 to method D. Is CR21 OK? Replace CR21. | |
| CR1 | Rotating Diode (CR1) | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| CR2 | Rotating Diode (CR2) | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| CR21 | Defective component on CR21 | ||
| CR3 | Rotating Diode (CR3) | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| CR4 | Silicon Controlled Rectifier (SCR) 4 | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| CRS | Silicon Controlled Rectifier (SCR) S | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| DS12 | Emergency Shutdown | ||
| DS13 | Low Oil Pressure | ||
| DS14 | High Water Temperature | ||
| DS15 | Overspeed | ||
| E | ENGINE MALFUNCTION SHUTDOWN | ||
| F | LOW OIL PRESSURE SHUTDOWN | ||
| G | HIGH WATER TEMPERATURE SHUTDOWN | ||
| Generator overvoltage | Generator overvoltage. | A. Replace SCR block. b. Replace voltage regulator. | |
| H | OVERSPEED CONDITION | ||
| High engine temperature | *High engine temperature shutdown. | A. Coolant level. Replenish is necessary. b. City water cooled sets. Check water flow, valves, etc. c. Check sensor; check thermostat. d. Radiator model, check fan belts, radiator for obstructions, etc. | |
| K1 relay LED | Engine Run Relay | ||
| K2 relay LED | Engine Crank Relay | ||
| K3 relay LED | AC Crank Disconnect Relay | ||
| K4 relay LED | Fault Shutdown Relay | ||
| K5 relay LED | Time Delay Control (Start/Run) | ||
| LOP | Low Oil Pressure | ||
| Low oil pressure | *Low oil pressure shutdown. | A. Oil level. Replenish if necessary. b. Sensor. Faulty sensor will shut down engine. | C. Refer to engine service manual for troubleshooting guide for oil system. |
| Overspeed | Overspeed shutdown. | Check governor and throttle linkages for freedom of movement. | |
| T21 | Reference Transformer (T21) | Check continuity between VR21-1 and T7, apply shorting jumper if no continuity. Replace circuit breaker CB21 if necessary. | |
| VR1 | Voltage Regulator VR1 | ||
| VR21 | Fault in VR21 voltage regulator |
| Symptom | Remedy |
|---|---|
| *High engine temperature light ON. | 8. Disconnect wire at TB11-31. Light ON after relay reset. Replace engine monitor board. |
| *Low oil pressure light ON. | 7. Disconnect wire at TB11-30. Light ON after relay reset. Replace engine monitor board. |
| AC circuit breaker tripping due to overload on generator set | Reduce load (see Wattage Requirements) |
| Bad or stale fuel | Replace |
| Both Field Rectifiers are defective. | Test rectifiers and replace both if defective. |
| Carbon build-up | Have unit serviced by an authorized Kohler service dealer/distributor |
| Carburetor adjustment wrong | Adjust |
| Coolant level is not correct. | Disconnect wire from TB11-30. Does light remain ON? (YES: Replace Engine Monitor module A14. NO: Is coolant level correct? If city water cooled, is input solenoid valve open?) |
| Defective battery charging alternator | Contact generator service dealer/distributor |
| ENGINE FAILS TO CRANK. SWITCH IN “REMOTE” POSITION. | Are switches in correct starting position? Set-control panel R-S-R switch to Remote? Remote station switch to Start? (YES: Go to next step; NO: Check wiring between generator set and remote station. Repair where necessary.) |
| ENGINE FAILS TO CRANK. SWITCH IN “RUN” POSITION. | Are batteries connected properly, is voltage normal? (YES: Go to next step; NO: Replace batteries or check connections) |
| Engine malfunction shutdown, fault light “ON”. | Which of the following fault lamps is lit (a) Overcrank (after 75-seconds)? (b) Overspeed? (c) Low Oil Pressure? (d) High Engine Temperature? (YES: Go to next step; NO: Check fuel system. Are valves open? Tanks fuil?) |
| Engine overload | Reduce load |
| Engine runs, shuts down and cranks for 75-seconds. Cranking cycle stops; fault lamp lights. | Check for dirty fuel filters and replace if necessary. (See MAINTENANCE section). Check for dirty or plugged air filters and replace if necessary. (See MAINTENANCE section) |
| Engine runs, shuts down, cranks for 75-seconds, cranking cycle stops, light ON. | Check fuel supply. |
| Engine runs, shuts down, cranks for 75-seconds, cranking cycle stops, overcrank light ON. | Check for dirty fuel filters and replace if necessary. (See MAINTENANCE section). Check for dirty or plugged air filters and replace if necessary. (See MAINTENANCE section) |
| Engine starts from generator control panel but will not start automatically or from a remote panel, (Note: The Run/Stop/Remote switch must be in the Remote position for automatic or remote starting). | Remote circuit breaker is tripped, Reset breaker and restart. Contact an Onan Dealer or Distributor if breaker trips after resetting. |
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.