Controller displays F04 – Low oil pressure shutdown shortly after start

Safety first: Do not continue to crank or run an engine with a low oil pressure alarm. Severe engine damage can occur.

• Check oil level: With the engine off and cooled, use the dipstick to verify oil level. Top up with MTU-approved engine oil to the correct mark if low.
• Inspect for leaks: Look around the oil pan, filter housing, cooler, and external lines for signs of oil leakage. Repair any leaks before restarting.
• Verify oil filter condition: If the oil and filter are overdue for service or appear contaminated, perform an oil and filter change using the correct MTU filter element.
• Test oil pressure sensor: Locate the oil pressure sender on the engine block. Check the electrical connector and wiring back to the MTU controller. If possible, temporarily install a mechanical gauge to confirm actual oil pressure during cranking/start.
• Sensor replacement: If mechanical pressure is normal but the controller still shows low pressure, replace the oil pressure sensor with an MTU-specified part.
• Do not run with true low pressure: If both the mechanical gauge and controller indicate low pressure, shut down immediately and contact an MTU service technician. The oil pump or internal engine components may be failing.