Detroit Diesel fault codes for DD13, DD15, and DD16 engines can indicate emissions problems, derate conditions, DEF issues, or sensor failures. Below you’ll find common SPN & FMI codes with explanations and repair guidance.
Watch: Detroit Diesel Fault Codes Explained
This video breaks down how Detroit Diesel fault codes work on DD13, DD15, and DD16 engines, including how SPN and FMI codes identify specific system failures. Learn what common DPF, SCR, and derate-related codes mean, how emissions systems trigger power reduction, and what steps drivers should take before roadside breakdown occurs. If a fault leads to engine derate or performance issues, use 4RoadService to quickly locate truck repair and mobile service near you.
How Detroit Diesel Fault Codes Work
Detroit Diesel engines use SPN (Suspect Parameter Number) and FMI (Failure Mode Identifier) codes to identify system faults. These codes help diagnose issues related to emissions systems, engine performance, sensors, and aftertreatment components. Understanding the meaning of each SPN and FMI combination can help determine whether immediate repair is required.
Common Detroit Diesel SPN & FMI Codes Explained
Below is a growing list of Detroit Diesel SPN and FMI fault codes commonly found on DD13, DD15, and DD16 engines. Each code page explains symptoms, causes, whether you can continue driving, and recommended actions.
Common Detroit Diesel Fault Codes
- Detroit Diesel SPN 1127 FMI 16 – Exhaust Back Pressure High.
- Detroit Diesel SPN 3826 FMI 16 – DPF Incomplete Regeneration
- Detroit Diesel SPN 3700 FMI 1 – DPF Outlet Temperature Low
- Detroit Diesel SPN 3700 FMI 16 – DPF Outlet Temperature High
- Detroit Diesel SPN 3713 FMI 16 – DPF Soot Load High
- Detroit Diesel SPN 3713 FMI 18 – DPF Soot Load Critical
- Detroit Diesel SPN 3719 FMI 0 – DPF Soot Level High
- Detroit Diesel SPN 3364 FMI 2 – DEF Quality / Sensor Fault
- Detroit Diesel SPN 3250 FMI 16 – DPF Differential Pressure High
- Detroit Diesel SPN 3480 FMI 16 – DPF Ash Load High
- Detroit Diesel SPN 4353 FMI 18 – DEF Injection Quantity Low
- Detroit Diesel SPN 3936 FMI 1 – DEF Level Low
- Detroit Diesel SPN 3031 FMI 1 – DEF Tank Temperature Low
- Detroit Diesel SPN 3031 FMI 16 – DEF Tank Temperature High
- Detroit Diesel SPN 4094 FMI 18 – DEF Dosing Low Flow
- Detroit Diesel SPN 3509 FMI 16 – DEF Concentration Out of Range
- Detroit Diesel SPN 3556 FMI 16 – Hydrocarbon Dosing Injector Fault
- Detroit Diesel SPN 4076 FMI 18 – DEF Dosing Injector Fault
- Detroit Diesel SPN 3363 FMI 16 – DEF Pump Pressure High
- Detroit Diesel SPN 3362 FMI 1 – DEF Pump Pressure Low
- Detroit Diesel SPN 4334 FMI 16 – SCR Conversion Efficiency Low
- Detroit Diesel SPN 1569 FMI 31 – Engine Protection Derate
- Detroit Diesel SPN 520372 FMI 16 – SCR Efficiency Below Threshold
- Detroit Diesel SPN 5246 FMI 0 – Aftertreatment System Fault
- Detroit Diesel SPN 4360 FMI 18 – Aftertreatment SCR Inducement Active
- Detroit Diesel SPN 4374 FMI 18 – DEF Doser Valve Current Low
- Detroit Diesel SPN 4375 FMI 18 – DEF Doser Valve Response Fault
- Detroit Diesel SPN 4364 FMI 18 – EGR Flow Fault
- Detroit Diesel SPN 102 FMI 18 – Intake Manifold Pressure High
- Detroit Diesel SPN 111 FMI 1 – Engine Coolant Temperature High
- Detroit Diesel SPN 94 FMI 1 – Fuel Pressure Low
- Detroit Diesel SPN 4334 FMI 18 – SCR Conversion Efficiency Low
- Detroit Diesel SPN 520372 FMI 18 – SCR Efficiency Below Threshold Severe
- Detroit Diesel SPN 2659 FMI 0 – EGR Valve Position Fault
- Detroit Diesel SPN 3216 FMI 21 – DPF Regeneration Frequency High
- Detroit Diesel SPN 3242 FMI 16 – DPF Inlet Temperature High
- Detroit Diesel SPN 3242 FMI 1 – DPF Inlet Temperature Low
- Detroit Diesel SPN 3251 FMI 0 – NOx Sensor Fault
- Detroit Diesel SPN 3251 FMI 16 – NOx Sensor Downstream High
- Detroit Diesel SPN 3251 FMI 18 – DPF Differential Pressure Sensor Fault
- Detroit Diesel SPN 3230 FMI 2 – NOx Sensor Rationality Fault
- Detroit Diesel SPN 3216 FMI 2 – NOx Sensor Upstream Rationality Fault
- Detroit Diesel SPN 3697 FMI 16 – Aftertreatment Fuel Pressure Low
- Detroit Diesel SPN 3698 FMI 16 – Aftertreatment Fuel Pressure High
- Detroit Diesel SPN 3720 FMI 16 – DPF Soot Load Percent High
- Detroit Diesel SPN 4766 FMI 31 – DPF Active Regeneration Inhibited
- Detroit Diesel SPN 100 FMI 1 – Engine Oil Pressure Low
- Detroit Diesel SPN 171 FMI 3 – Ambient Air Temperature Sensor Voltage High
- Detroit Diesel SPN 27 FMI 9 – EGR Valve Position Error
- Detroit Diesel SPN 27 FMI 11 – EGR Valve Circuit Fault
Why Detroit Diesel Fault Codes Should Not Be Ignored
Many Detroit Diesel fault codes trigger progressive derate conditions that reduce engine power or limit vehicle speed. Addressing codes early can prevent costly breakdowns and roadside emergencies. Always diagnose the underlying issue before clearing active codes.
Most Common Detroit Diesel Fault Categories
- DPF (Diesel Particulate Filter) faults
- SCR (Selective Catalytic Reduction) efficiency issues
- DEF (Diesel Exhaust Fluid) system faults
- EGR (Exhaust Gas Recirculation) faults
- Engine protection and derate conditions