SPN 1000 FMI 0Body
Driver Door Ajar Circuit Malfunction
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 1000 / FMI 0
Category
Body
Derate Risk
No
Regen Inhibit
No
Inducement Risk
No
Component Location: Driver door ajar switch is located inside the door latch assembly or mounted separately on the door jamb pillar on the driver side of the cab.
Common Symptoms
- Driver door ajar warning light remains illuminated with door closed
- Interior dome light stays on while driving
- Repeated chime or audible alert indicating door open when door is latched
- Battery drain due to interior lights remaining active
- Door ajar indicator on instrument cluster does not extinguish after closing door
- Intermittent or stuck door open signal observed on diagnostic scan tool
Root Causes
- Door ajar switch failure (stuck closed or open internally)
- Corroded or damaged door ajar switch connector/terminals
- Damaged wiring harness or chafed wire in door jamb area due to repeated door cycling
- Body Control Module (BCM) input circuit fault or software issue
- Door latch assembly worn or misaligned causing intermittent switch actuation
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
Mileage / Regen Notes
SPN 1000 FMI 0 is a body/cab circuit fault and does not directly inhibit or affect DPF regeneration cycles under standard OEM logic.
System Interactions
SPN 1000 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.
Related Faults in This Category
OEM System Resources
ASE Training Resources
Diagnostic Engine v7.0
Related Diagnostic Articles
Deep-dive diagnostic page: SPN 1000 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.
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 1000 FMI 0
The diagnostic engine walks you through every physical test — step by step, on your phone, at the truck. No guessing. No wasted parts.