The Governor Board A12) is a generator-set controller. It is used on generator sets from Cummins/Onan, including the GHA.
| Code | Meaning | Remedy |
|---|---|---|
| 35 | Checksum Fault | |
| 36 | Engine Stopped | -Check Fuel pressure -Governor operation -Spark -Loads -Control -Quad voltage -Quad windings -Air temperature switch |
| 38 | Field Overload | -Check Intake/exhaust restrictions -Control -Rotor and brushes -Power factor of loads |
| 42 | Processor Fault − ROM | -Check -Verify fault -Control |
| 43 | Processor Fault − RAM | -Check -Verify fault -Control |
| 45 | Zero Cross Sense Loss | -Check Field flash -Quad voltage -Quad winding -Quad wiring -Rotor and brushes -Control |
| 46 | Overcrank | -Check Fuel pressure -Spark -Battery level -Control |
| 48 | Loss of Field Sense | -Check -Verify fault -Control |
| Symptom | Remedy |
|---|---|
| Engine Cranks But Will Not Start | - Check Battery condition - Perform checks in step 01 - Check Fuel supply - Perform checks in step 01 - Check Ignition spark - Perform checks in step 01 - Check Spark plug - Perform checks in step 01 - Check Fuel pressure at carburetor - Perform checks in step 01 - Check Carbueretor piston for free movement - Perform checks in step 01 - Check Governor linkage - Perform checks in step 01 - Check Carburetor adjustments |
| Engine Oil Leak | - Clean contaminated area - Run engine and check for leaks - Add dye to oil and check for leaks |
| Engine Overfueling (Genset) | - Check Spark plug - Perform checks in step 01 - Check Fuel pressure at carburetor - Perform checks in step 01 - Check Carbueretor piston for free movement - Perform checks in step 01 - Check Governor linkage - Perform checks in step 01 - Check Carburetor adjustments |
| Engine Starts But Stops When Switch is Released | - Check Fuel pressure - Perform checks in step 01 - Check AC output when running - Perform checks in step 01 - Check Quadrature voltage - Perform checks in step 01 - Check Remote start/stop switch - Perform checks in step 01 - Check ATS input control - Evaluate fault codes, if present |
| Engine Unstable (Hunts) (Genset) | - Check Fuel supply - Perform checks in step 01 - Check Fuel lines for leakage - Perform checks in step 01 - Check Loose wiring connections - Perform checks in step 01 - Check Governor linkage for binding - Perform checks in step 01 - Check Governor adjustments - Perform checks in step 01 - Check Carburetor piston for free movement |
| Engine Will Not Crank | - Check Battery condition - Perform checks in step 01 - Check Battery connections - loose or dirty - Perform checks in step 01 - Check Battery cable size - Perform checks in step 01 - Evaluate fault codes - Perform checks in step 01 - Check Starter - Perform checks in step 01 - Check Start/Stop switch - Perform checks in step 01 - Check Remote connections - Perform checks in step 01 - Check Start solenoid - Perform checks in step 01 - Control - Perform checks in step 01 |
| Fault Code 12 (Over Voltage) | - Check Output voltage |
| Fault Code 13 (Under Voltage) | - Check Loads - Perform checks in step 01 - Check Rotor and brushes - Perform checks in step 01 - Check Stator |
| Fault Code 14 (Over Frequency) | - Check Engine speed - Perform checks in step 01 - Check Loads - Perform checks in step 01 - Check Control |
| Fault Code 15 (Under Frequency) | - Check Engine speed - Perform checks in step 01 - Check Control |
| Fault Code 27 (Loss of AC Sense) | - Check Wiring from generator to control - Perform checks in step 01 - Check Generator stator - Perform checks in step 01 - Check Generator rotor - Perform checks in step 01 - Check Control - External shorts |
| Fault Code 29 (High Battery Voltage) | - Check Battery connections - Perform checks in step 01 - Check Battery charge rate - Perform checks in step 01 - Check Battery condition |
| High AC Output (Genset) | - Check Broken or loose wires - Perform checks in step 01 - Check Output lead wiring configuration - Perform checks in step 01 - Check Control connections at control - Evaluate fault codes, if present |
| No AC Output (Genset) | - Check Load breakers closed - Perform checks in step 01 - Check Broken or loose wires - Perform checks in step 01 - Check Output to load breakers - Perform checks in step 01 - AC output - Evaluate fault codes, if present |
| Starter Fault | - Check Battery voltage - Perform checks in step 01 - Check Battery condition - Perform checks in step 01 - Check Battery connections - Perform checks in step 01 - Check Starter - Perform checks in step 01 - Check External loads |
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.