SPN 1382 FMI 21ABS
EBS Communication Timeout - Data Drifted High
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
DieselVision™ Upload photos — DieselVision™ reads diagrams, connectors, and screens with precision.
Overview
Fault Code
SPN 1382 / FMI 21
Category
ABS
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: The EBS control module is typically mounted on the frame rail near the rear axle or in the chassis electrical center.
Common Symptoms
- ABS warning lamp illuminated on dash
- Loss of electronic stability control function
- Electronic brake system derate or degraded braking performance
- Communication fault codes for brake system modules
- Intermittent loss of trailer ABS communication
Root Causes
- Faulty EBS control module or ECU Corroded or damaged wiring harness connections in brake system CAN network Intermittent CAN bus communication fault between tractor and trailer Failed wheel speed sensor affecting EBS data integrity Power supply issue to EBS control module
Full step-by-step tests, DVOM guidance, and pinout data are available inside the AI Diesel Tech diagnostic session.
AI walks you through every test — one step at a time. Plans start at $12.95/mo.
Derate Behavior
Power Derate
No
System Interactions
SPN 1382 FMI 21 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.
Related Faults in This Category
OEM System Resources
ASE Training Resources
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 1382 FMI 21 — Full FSM Sequence & Repair Steps — includes wiring notes, sensor specs, and gated repair procedures.
Authority References
Diagnostic procedures on this page are informed by OEM service literature and industry standards.
Cummins QuickServe OnlineOfficial Cummins service manuals, fault code lookup, and TSB database.Detroit Diesel DiagnoCentralDetroit Diesel diagnostic procedures, DDDL documentation, and service literature.PACCAR MX Engine ServicePACCAR MX-11 and MX-13 engine service documentation and DAVIE diagnostic guides.Volvo/Mack Tech ToolVolvo and Mack engine fault code reference and PTT/Tech Tool diagnostic procedures.ASE — Diesel Truck Technician CertificationNational Institute for Automotive Service Excellence — T2 Diesel Engines certification standards.EPA Aftertreatment & Emissions GuidelinesU.S. EPA heavy-duty diesel aftertreatment compliance, DPF/SCR regulations, and NOx standards.
Get weekly diesel diagnostic tips
Real-world fault code walkthroughs, wiring tips, and shop-tested fixes — free.
No spam. Unsubscribe anytime.
Get AI-Guided Diagnosis for SPN 1382 FMI 21
The diagnostic engine walks you through every physical test — step by step, on your phone, at the truck. No guessing. No wasted parts.