AI Diesel Tech

Fault Code Reference

SPN 1484 FMI 31ABS

Traction Control - Condition Exists

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DVOM Testing — in guided session

Connector Pinout — in guided session

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Overview

Fault Code

SPN 1484 / FMI 31

Category

ABS

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: WABCO ABS control module is typically mounted on the frame rail near the rear axle assembly or on the chassis firewall.

Common Symptoms

  • Traction control warning lamp illuminated on dash
  • ABS warning lamp may also be illuminated
  • Traction control system disabled or inactive
  • Loss of traction control intervention during wheel slip
  • Vehicle stability control may be limited

Root Causes

  • Wheel speed sensor fault or signal dropout ABS control module detecting traction control condition Faulty wheel speed sensor tone ring or reluctor CAN bus communication issue between ABS and ECU Low system voltage affecting traction control operation

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 1484 FMI 31 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 1484 FMI 31 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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