SPN 140 FMI 0NetworkMedium
Lost Communication With Body Control Module
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
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Overview
Fault Code
SPN 140 / FMI 0
Category
Network
Severity
Medium
Regen Inhibit
No
Inducement Risk
No
Component Location: BCM is typically located in the cab, often behind the dash, under the passenger seat, or in a dedicated electrical panel box depending on OEM and body builder.
Common Symptoms
- Loss of communication with Body Control Module (BCM) on diagnostic scan tool
- Multiple body-related electrical systems inoperative (lights, wipers, accessories)
- CAN bus communication errors across multiple modules
- Warning lights illuminated on dash
- Intermittent or complete loss of J1939 network communication
- Engine may not start or exhibits abnormal starting behavior
Root Causes
- Blown fuse or open circuit in BCM power supply circuit Poor ground connection at BCM or chassis ground point Corroded or damaged connector at BCM harness plug CAN bus wiring fault (open, short to ground, or short to voltage) Damaged or faulty CAN terminating resistor Water intrusion into BCM connector or housing Failed or damaged Body Control Module Improper or missing CAN bus termination resistor
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System Interactions
SPN 140 FMI 0 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.
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OEM System Resources
ASE Training Resources
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Related Diagnostic Articles
Deep-dive diagnostic page: SPN 140 FMI 0 — 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.
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