The Run-Off-Auto switch is a generator-set controller. It is used on generator sets from Cummins/Onan, including the GRCA.
| Code | Meaning | Cause | Remedy |
|---|---|---|---|
| 2 | LOW OIL PRESSURE FAULT—CODE NO. 2 | The controller sensed that the low oil pressure cutoff did not open within 10 seconds of starting | 1. Check engine oil level and add oil as necessary. Repair oil leaks. 2. Drain excess oil. (Excess oil leads to foaming and a consequent loss of oil pressure.) 3. If the oil level is OK, contact Cummins/Onan Service. |
| 3 | SERVICE CHECK FAULT—CODE NO. 3 | 1. Reduce the number of appliances running at the same time, especially those with high motor starting loads such as air conditioners. 2. Open any closed fuel valves and check for an adequate fuel supply. 3. Check for fouled spark plugs. 4. Check air cleaner. 5. Clean and tighten the positive (+) and negative (-) genset battery cable connections. 6. If the condition still exists, contact Cummins/Onan Service. | |
| 4 | OVERCRANK FAULT—CODE NO. 4 | 1. Check fuel level. 2. Open any closed fuel valves. 3. Secure the spark plug lead on the spark plug. 4. Check the spark plugs. 5. Service the air cleaner. | |
| Code No. 4 | Code No. 4: blink-blink-blink-blink |
| Symptom | Remedy |
|---|---|
| Electrolyte is a dilute sulfuric acid that is harmful to the skin and eyes. It is electrically conductive and corrosive. | (1) Wear full eye protection and protective clothing, (2) Where electrolyte contacts the skin, wash it off immediately with water and seek medical attention, (3) Where electrolyte contacts the eyes, flush thoroughly and immediately with water and seek medical attention, (4) Spilled electrolyte is to be washed down with an acid neutralizing agent. A common practice is to use a solution of one pound (500 grams) bicarbonate of soda to one gallon |
| Engine does not start | See Troubleshooting in Section 4 |
| Engine does not start after 20 seconds of cranking | See Troubleshooting in Section 11 if the engine does not start. |
| Fuel or exhaust leak | Stop the genset immediately and have it repaired before continuing operation. |
| NO POWER—GENSET RUNNING, RUN LIGHT ON (Line circuit breaker OFF or tripped or faulty wiring) | 1. Turn on or reset the line circuit breaker on the genset. 2. Turn on or reset the line circuit breakers on the main distribution panel 3. If the condition still exists, contact Cummins/Onan service. |
| STARTING BATTERIES RUN DOWN (Marginal batteries, connections, or charging system or parasitic loads) | 1. Clean and tighten the positive (+) and negative (–) genset battery cable connections. 2. Recharge or replace the battery. Refer to the battery manufacturer's recommendations. 3. Have a battery charging system installed or serviced. |
| STarter ENGAGES–DISENGAGES (Cranking voltage dips below 6 volts—low battery charge, poor connections, long cables) | 1. Clean and tighten the positive (+) and negative (-) genset battery cable connections. 2. Recharge or replace the battery. Refer to the battery manufacturer's recommendations. |
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.