Magnum MMG235 troubleshooting: 2 fault codes and 10 symptom-cause-remedy entries from the manufacturer's own service documentation.
Magnum MMG235 — full specs, parts & maintenance.
| Code | Meaning |
|---|---|
| SD | Sensor fail (FLS) |
| WRN | Warning (WRN) |
| Symptom | Cause | Remedy |
|---|---|---|
| Low fuel level shut down | Fuel level low or inaccurate reading; leaks in the fuel tank; fuel level sender and connecting wiring damaged | Check the fuel level on the LCD window and confirm the generator is sitting level; check for leaks in the fuel tank; check the fuel level sender and the connecting wiring for damage and check for continuity between the sender and the engine controller |
| Low oil pressure shut down | Low engine oil level; oil leaks; loss of oil pressure; faulty oil pressure sender | Check the level of the engine oil with the dipstick and add oil if required; visually inspect the engine for oil leaks; restart the unit and verify the loss of oil pressure, shutting the engine down immediately if the oil pressure value does not read five psi (34 kPa) within five seconds; check the oil pressure sender and refer to the troubleshooting section of the engine operation and maintenance manual |
| Low coolant level shut down | Low coolant level; leaks in coolant hoses, engine block or water pump; coolant mixed with engine oil | Allow the engine to cool; check the coolant level in the radiator and add coolant until it is 3/4" below the filler neck, then secure the radiator cap; inspect coolant hoses, engine block and water pump for visible leaks; check engine oil to verify no coolant has mixed with it and consult the engine operation and maintenance manual |
| High coolant temperature shut down | Low coolant level; blocked radiator shroud and ducting; leaks in coolant hoses, engine block or water pump; loose serpentine drive belt for the water pump; engine overheating | Check the coolant level in the overflow jug; restart the engine and read the coolant temperature to verify High Coolant Temperature Shut down, stopping the engine immediately if the coolant temperature is 230°F (110°C) or more; allow the engine to cool, add coolant to the overflow jug if it is low and check the level of coolant in the radiator, adding coolant until it is 3/4" below the filler neck and securing the radiator cap; check the radiator shroud and ducting for blockage and remove any foreign matter; inspect coolant hoses, engine block and water pump for visible leaks; check the tension of the serpentine drive belt for the water pump; if no other problems are found, remove the load on the generator and restart the engine, checking the coolant temperature and shutting the engine down immediately if it starts to overheat, and consult the engine operation and maintenance manual |
| Overcrank shut down | Low fuel level in tank; improper operation of the fuel pump; blocked air filter; engine will not start | Check the fuel level in tank; check for proper operation of the fuel pump; check air filter for blockage; if the engine will not start, consult the engine operation and maintenance manual for additional information on troubleshooting starting problems |
| Overspeed or underspeed shut down | Frequency above or below 60.0 Hz; engine speed requires adjustment | Disconnect all loads and restart the generator, reading the frequency (Hz) on the LCD display (with no loads the frequency should read 60.0 Hz); if the frequency is above or below 60.0 Hz, adjust the engine speed — see the engine manual for throttle adjustments on mechanical governed units and the electronic governor manual for electronically controlled units |
| Low oil pressure shut down | Engine oil level low; oil leaks; loss of oil pressure; oil pressure sender faulty | Check the level of the engine oil with the dipstick and add oil if required; visually inspect the engine for oil leaks; restart the unit and verify the loss of oil pressure, shutting the engine down immediately if the oil pressure value does not read five psi (34 kPa) within five seconds; check the oil pressure sender and refer to the troubleshooting section of the engine operation and maintenance manual |
| Low coolant level shut down | Coolant level low; leaks in coolant hoses, engine block or water pump; coolant mixed with engine oil | Allow the engine to cool; check the coolant level in the radiator and add coolant until it is 3/4" below the filler neck; inspect coolant hoses, engine block and water pump for visible leaks; check engine oil to verify no coolant has mixed with it and consult the engine operation and maintenance manual |
| High coolant temperature shut down | Coolant level low; radiator shroud and ducting blocked; leaks in coolant hoses, engine block or water pump; serpentine drive belt for the water pump loose; engine overheating | Check the coolant level in the overflow jug; restart the engine and read the coolant temperature, stopping the engine immediately if the coolant temperature is 230°F (110°C) or more; allow the engine to cool, add coolant to the overflow jug if low and check the level of coolant in the radiator, adding coolant until it is 3/4" below the filler neck; check the radiator shroud and ducting for blockage and remove any foreign matter; inspect coolant hoses, engine block and water pump for visible leaks; check the tension of the serpentine drive belt for the water pump; if no other problems are found, remove the load on the generator and restart the engine, checking the coolant temperature and shutting the engine down immediately if it starts to overheat, and consult the engine operation and maintenance manual |
| Overcrank shut down | Fuel level low; fuel pump not operating properly; air filter blocked; engine will not start | Check the fuel level in tank; check for proper operation of the fuel pump; check air filter for blockage; if the engine will not start, consult the engine operation and maintenance manual for additional information on troubleshooting starting problems |
Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.
Documented causes: Low engine oil level; oil leaks; loss of oil pressure; faulty oil pressure sender; Engine oil level low; oil leaks; loss of oil pressure; oil pressure sender faulty. See the table for the matching fixes.
Documented causes: Low coolant level; leaks in coolant hoses, engine block or water pump; coolant mixed with engine oil; Coolant level low; leaks in coolant hoses, engine block or water pump; coolant mixed with engine oil. See the table for the matching fixes.
Documented causes: Low coolant level; blocked radiator shroud and ducting; leaks in coolant hoses, engine block or water pump; loose serpentine drive belt for the water pump; engine overheating; Coolant level low; radiator shroud and ducting blocked; leaks in coolant hoses, engine block or water pump; serpentine drive belt for the water pump loose; engine overheating. See the table for the matching fixes.