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Fault Code Reference

SPN 1125 FMI 11ABS

ABS System Configuration - Failure Mode Indicator

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DVOM Testing — in guided session

Connector Pinout — in guided session

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Overview

Fault Code

SPN 1125 / FMI 11

Category

ABS

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: ABS Electronic Control Unit is typically mounted on the frame rail near the axle or behind the cab in the chassis area.

Common Symptoms

  • ABS warning lamp illuminated on dash
  • Loss of ABS functionality with foundation brakes still operational
  • ABS system defaults to non-ABS braking mode
  • Traction control system disabled
  • Stability control features unavailable

Root Causes

  • ABS ECU configuration mismatch or corruption Incorrect vehicle parameters programmed in ABS controller Software version incompatibility between ABS components ABS ECU internal fault or memory error CAN bus communication error affecting configuration data

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 1125 FMI 11 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 1125 FMI 11 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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