AI Diesel Tech

Fault Code Reference

SPN 2228 FMI 0Sensors

Barometric Pressure Circuit Low

Scan Tool — in guided session

DVOM Testing — in guided session

Connector Pinout — in guided session

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Overview

Fault Code

SPN 2228 / FMI 0

Category

Sensors

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: Barometric pressure sensor is typically integrated into the ECM or mounted externally on the engine block or intake manifold.

Common Symptoms

  • Check Engine Light/MIL illuminated
  • Excessive black smoke during acceleration
  • Reduced engine power/performance
  • Poor fuel economy
  • Hard starting at altitude
  • Turbo boost limit issues
  • Failed emissions test

Root Causes

  • Faulty barometric pressure sensor Damaged or corroded wiring harness to barometric pressure sensor Shorted sensor circuit to ground ECM internal fault affecting sensor supply circuit Water intrusion in sensor connector

Full step-by-step tests, DVOM guidance, and pinout data are available inside the AI Diesel Tech diagnostic session.

AI walks you through every test — one step at a time. Plans start at $12.95/mo.

Derate Behavior

Power Derate

No

System Interactions

SPN 2228 FMI 0 interacts with the following systems and may trigger cascading faults if not resolved promptly.

Common Diagnostic Mistakes

Replacing the sensor without verifying wiring continuity and supply voltage first.

Clearing codes without identifying and resolving the root cause — the fault will return.

Ignoring related active faults — cascading faults often share a root cause.

Skipping the connector inspection — corrosion and damaged pins are a leading cause of sensor faults.

Condemning the ECM before exhausting all wiring and component tests.

Deep-dive diagnostic page: SPN 2228 FMI 0 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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