AI Diesel Tech

Fault Code Reference

SPN 1348 FMI 6ABS

ABS Modulator Valve - Front Axle Right - Current Above Normal/Shorted

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Connector Pinout — in guided session

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Overview

Fault Code

SPN 1348 / FMI 6

Category

ABS

Derate Risk

No

Regen Inhibit

No

Inducement Risk

No

Component Location: The ABS modulator valve is mounted on the ABS control module assembly, typically located on the frame rail near the front axle.

Common Symptoms

  • ABS warning lamp illuminated on dash
  • ABS system disabled or non-functional
  • Reduced braking performance or wheel lockup during hard braking
  • Audible clicking or buzzing from ABS modulator

Root Causes

  • Shorted ABS modulator solenoid valve coil Damaged or chafed wiring harness to modulator valve Water or moisture intrusion into ABS modulator connector Failed ABS control module driving excessive current Corrosion in modulator valve connector pins

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 1348 FMI 6 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 1348 FMI 6 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.

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