Fuel System Leak Detected - Large
The YANMAR-P0093 (Yanmar) diesel fault code means: Fuel System Leak Detected - Large. This is a serious severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- intermediate
- Estimated cost
- $30-$400
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Common Symptoms
- Hard start, fuel smell, slow priming
Probable Causes (Ranked by Likelihood)
- Leaking fuel return line on injector Likely
- Loose high-pressure fitting on rail or injector Possible
Step-by-Step Diagnostic Procedure
Inspect fuel lines with engine running (safety glasses required).
Smoke-test low-pressure fuel system.
Tighten/replace leaking fittings to Yanmar torque spec.
Frequently Asked Questions
What is Yanmar code P0093?
Yanmar P0093: Fuel System Leak Detected - Large. This code is reported on Yanmar equipment running the described engine family.
Can I keep working with Yanmar code P0093?
Do not continue operating. Risk of engine damage or unsafe shutdown.
How much does Yanmar P0093 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.
P0093 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown: