YANMAR-P0091 serious Yanmar ›

Fuel Pressure Regulator (SCV) Control Circuit Low

The YANMAR-P0091 (Yanmar) diesel fault code means: Fuel Pressure Regulator (SCV) Control Circuit Low. This is a serious severity code.

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Keep driving?
Limited driving only
DIY difficulty
intermediate
Estimated cost
$100-$700

What Are the Symptoms of YANMAR-P0091?

  • Derate, rough running

What Causes YANMAR-P0091? (Most Likely First)

  • Open or shorted SCV solenoid wiring Likely
  • Failed SCV solenoid Possible

Can I Still Drive with YANMAR-P0091?

Limited driving only. YANMAR-P0091 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What is Yanmar code P0091?

Yanmar P0091: Fuel Pressure Regulator (SCV) Control Circuit Low. This code is reported on Yanmar equipment running the described engine family.

Can I keep working with Yanmar code P0091?

Limited operation only -- finish the current task then shut down for repair.

How much does Yanmar P0091 cost to fix?

Estimated repair cost: $100-$700. Off-road diesel shop labor runs $125-$175/hr in 2026. Dealer diagnostic software (Yanmar SmartAssist / YDT) is usually required.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose YANMAR-P0091?

  1. Ohm-test SCV solenoid (spec per Yanmar service manual).

  2. Check harness continuity from ECU to SCV connector.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines P0091 as a generic OBD-II code)

P0091 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Gas / Automotive (OBD-II) Generic OBD-II definition for P0091 Duramax serious Fuel Pressure Regulator 1 Control Circuit Low Hino moderate Fuel Pressure Regulator 1 Circuit Low Isuzu moderate Fuel Pressure Regulator 1 Control Circuit Low Kubota serious Fuel Pressure Regulator Circuit Low PACCAR moderate Fuel Pressure Regulator 1 Control Circuit Low Power Stroke moderate Fuel Pressure Regulator Circuit Low

Which Vehicles Commonly Get YANMAR-P0091?

  • Yanmar SA221 / SA324 / SA424 compact tractors
  • Yanmar YT235 / YT347 / YT359 compact tractors
  • Yanmar LX4100 / LX4900 utility tractors
  • Yanmar ViO17 / ViO25 / ViO35 / ViO45 / ViO55 / ViO80 mini excavators
  • Yanmar B27-3 / B37-3 / B50-3 compact excavators
  • Cub Cadet Yanmar Ex3200 / Lx410 compact tractors (rebadged)
  • John Deere 17G / 26G / 35G compact excavators (Yanmar powered)
  • Takeuchi TB210R / TB216 / TB230 mini excavators (Yanmar powered)

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