Yanmar Marine Fuel System Low Pressure
The YANMAR-MARINE-FUEL-PRESSURE (Yanmar) diesel fault code means: Yanmar Marine Fuel System Low Pressure. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $30-$400
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Common Symptoms
- Surging at cruise
- Shutdown under load
Probable Causes (Ranked by Likelihood)
- Plugged primary (Racor) fuel filter Very Likely
- Air ingress from loose fitting / cracked hose Likely
- Failed electric lift pump Possible
Step-by-Step Diagnostic Procedure
Replace primary Racor filter; note vacuum gauge reading.
Smoke-test suction side of fuel system.
Test lift pump pressure.
Frequently Asked Questions
What is Yanmar code MARINE-FP?
Yanmar MARINE-FP: Yanmar Marine Fuel System Low Pressure. This code is reported on Yanmar equipment running the described engine family.
Can I keep working with Yanmar code MARINE-FP?
Limited operation only -- finish the current task then shut down for repair.
How much does Yanmar MARINE-FP cost to fix?
Typical repair cost: $30-$400. Off-road diesel shop labor runs $125-$175/hr in 2026. Dealer diagnostic software (Yanmar SmartAssist / YDT) is usually required.