SPN 1443 FMI 4ABS
Lateral Acceleration Sensor - Voltage Below Normal
Scan Tool — in guided session
DVOM Testing — in guided session
Connector Pinout — in guided session
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Overview
Fault Code
SPN 1443 / FMI 4
Category
ABS
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: The lateral acceleration sensor is typically mounted on the vehicle frame rail near the center of the wheelbase or integrated into the ABS ECU module.
Common Symptoms
- ABS warning lamp illuminated
- Stability control system disabled
- Roll stability warning light active
- ESC/RSC functionality unavailable
- Traction control disabled
- ABS may remain functional but stability features lost
Root Causes
- Faulty lateral acceleration sensor Damaged or corroded wiring harness to lateral acceleration sensor Poor ground connection at sensor Water intrusion or moisture in sensor connector Faulty ABS ECU supply voltage circuit
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Derate Behavior
Power Derate
No
System Interactions
SPN 1443 FMI 4 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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Related Diagnostic Articles
Deep-dive diagnostic page: SPN 1443 FMI 4 — 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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