AI Diesel Tech

Fault Code Reference

SPN 3515 FMI 2ABS

Roll Stability Control Yaw Rate Sensor - Data Erratic/Intermittent

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Connector Pinout — in guided session

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Overview

Fault Code

SPN 3515 / FMI 2

Category

ABS

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: The yaw rate sensor is typically mounted on the vehicle frame near the center of the chassis to accurately measure vehicle rotation.

Common Symptoms

  • ABS warning lamp illuminated
  • Stability control warning light active
  • Roll stability control system disabled
  • Intermittent loss of stability control intervention
  • Vehicle may not detect rollover risk conditions

Root Causes

  • Faulty yaw rate sensor Intermittent wiring connection to yaw rate sensor Corroded or damaged sensor connector Sensor mounting bracket loose or damaged ECU internal fault

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

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Derate Behavior

Power Derate

No

System Interactions

SPN 3515 FMI 2 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 3515 FMI 2 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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