The Circuit Board is a generator-set controller. It is used on generator sets from Generac, including the Q-55G and Q-70G.
| Symptom | Cause | Remedy |
|---|---|---|
| Engine cranks, won't start | 1. Out of fuel. 2. Fuel shutoff valve is closed. 3. Fuel pump not operating. 4. Automatic choke not operating properly. 5. Engine is flooded. 6. Fuel filter is clogged. 7. Defective control relay (CR2). 8. Engine spark plugs defective. 9. Bad ignition magneto on engine. 10. Bad carburetor. 11. Dirty air cleaner. | 1. Refill fuel tank. 2. Open fuel shutoff valve(s). 3. Repair or replace pump. 4. Repair, replace or adjust properly. 5. Wait 5-10 minutes; try again. 6. Replace filter if clogged. 7. Replace bad relay (CR2). 8. Clean, regap or replace as needed. 9. Replace if defective. 10. Adjust, repair or replace. 11. Clean or replace as needed. |
| Engine cranks, won’t start | 1. Out of fuel. 2. Fuel shutoff valve is closed. 3. Fuel pump not operating. 4. Automatic choke not operating properly. 5. Engine is flooded. 6. Fuel filter is clogged. 7. Defective control relay (CR2). 8. Engine spark plugs defective. 9. Bad ignition magneto on engine. 10. Bad carburetor. 11. Dirty air cleaner. | 1. Refill fuel tank. 2. Open fuel shutoff valve(s). 3. Repair or replace pump. 4. Repair, replace or adjust. 5. Wait 5*10 minutes; try again. 6. Replace filter if clogged. 7. Replace bad relay (CR2). 8. Clean, regap or replace as needed. 9. Replace if defective. 10. Adjust, repair or replace. 11. Clean or replace as needed. |
| Engine does not start after cranking for 15 seconds | Release the start/stop switch and try again | |
| Engine failure | Attempted cranking or starting engine before proper oil servicing | Properly service engine crankcase with recommended oil |
| Engine starts hard, runs rough | 1. Dirty engine air cleaner. | 1. Clean or replace as needed. |
| Engine starts, then shuts down | 1. Engine oil level is low 2. Bad control relay (CR1). 3. Bad low oil pressure switch. 4. Bad control relay (CR2). 5. Water in fuel. | 1. Add oil as needed. 2. Replace if bad (CR1). 3. Replace, if bad. 4. Replace bad relay (CR2). 5. Drain fuel tank and refill. |
| Engine won't crank | 1. 15 amp fuse blown. 2. Loose, corroded or defective battery 3. Transfer switch (if so equipped) is set to wrong position. 4. Failure in vehicle electrical system. 5. Generator component failure. | 1. Replace blown fuse. 2. Tighten, clean or replace, as necessary. 3. Set transfer switch correctly if equipped. 4. Check and repair the vehicle's electrical system. 5. Inspect and replace any faulty generator components. |
| Engine won’t crank | 1. 15 amp fuse blown. 2. Loose, corroded or defective battery cable(s). 3. Battery is discharged or defective. 4. Defective starter contactor. 5. Defective starter motor. 6. Defective control relay (CR1). | 1. Replace blown fuse. 2. Tighten, clean or replace, as necessary. 3. Recharge or replace battery. 4. Replace starter contactor. 5. - Replace starter motor. 6. Replace control relay. |
| Exhaust gases entering vehicle interior | Openings in the vehicle that might permit exhaust gases to enter | Close windows, doors, and other openings in the vehicle |
| Generator overheating and shutdown | Insufficient cooling and ventilating air flow | Ensure air inlet and outlet openings in generator compartment are open and unobstructed |
| No AC output voltage | 1. Main breaker(s) open. 2. Transfer switch (if so equipped) is set to wrong position. 3. Failure in vehicle electrical system. 4. Generator component failure. | 1. Close main breaker(s). 2. Reset transfer switch. 3. See vehicle manual. 4. Contact authorized service facility. |
| The Start/Stop switch is set to Stop, but the engine continues to run. | 1. Defective Start/Stop switch 2. Open/Disconnected #18 wire between Start/Stop switch and engine control board 3. Open/Disconnected #0 wire betw | 1. Replace switch. 2. Reconnect or close wire. 3. Reconnect or close wire. |
| The engine cranks but will not start. | 1. Out of fuel 2. Defective fuel pump 3. Open #14 wire from engine control board insulation of #14 wires. 4. Flooded engine 5. Defective spark plug(s) 6. Fuel line shut-off closed 7. Plugged fuel filter | 1. Replenish fuel. 2. Replace fuel pump. 3. Check connections and/or insulation of #14 wires. 4. Wait 5-10 minutes before trying. 5. Clean, re-gap or replace plug(s). 6. Open fuel line shut-off. 7. Clean or replace fuel filter. |
| The engine starts hard and runs rough. | 1. Air cleaner plugged or damaged | Check, clean or replace air cleaner. |
| The engine starts, but shuis down when the Start/Stop switch is released. | 1. Engine oil level low 2. Defective low oil pressure switch 3. Defective high temperature switch 4. Defective engine control board 5. Overheated engine | 1. Check oil and add oil as needed. 2. Replace pressure switch. 3. Replace temperature switch. 4. Replace control board. 5. Check that the airflow openings are adequate. |
| The engine will not crank. | 1. Fuse blown 2. Loose, corroded or defective battery cables as necessary. 3. Defective engine Start/Stop switch 4. Defective starter contactor 5. Defective starter motor | 1. Replace fuse. 2. Tighten, clean or replace battery cables as necessary. 3. Replace Start/Stop switch. 4. Replace contactor. 5. Replace starter motor. |
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.