AI Diesel Tech

Fault Code Reference

SPN 1574 FMI 7ABS

EBS Brake Pressure Modulator - Mechanical System Not Responding

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DVOM Testing — in guided session

Connector Pinout — in guided session

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Overview

Fault Code

SPN 1574 / FMI 7

Category

ABS

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: The EBS brake pressure modulator is typically mounted on the frame rail near the air brake system components or integrated into the ABS control unit.

Common Symptoms

  • ABS warning lamp illuminated on dash
  • EBS malfunction indicator active
  • Reduced braking performance or uneven brake application
  • Loss of ABS or stability control functionality
  • Brake pressure imbalance between axles

Root Causes

  • Faulty EBS pressure modulator valve stuck or binding Air system contamination or moisture in brake lines Internal mechanical failure of modulator solenoid or piston Blocked or restricted air supply to modulator Damaged or worn modulator seals causing internal leakage

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 1574 FMI 7 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 1574 FMI 7 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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