Code Details
| Display code | SPN 3055 FMI 14 |
|---|---|
| SPN | 3055 |
| FMI | 14 |
| OEM code | None listed |
| Manufacturer | Cummins |
| System | Aftertreatment �?DPF |
| Component | DPF / aftertreatment system / regeneration system |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-12 |
Plain-English Meaning
Under normal conditions, the ISX15 and X15 DPF regenerates automatically during highway driving when exhaust temperatures are high enough. When the DPF soot load becomes too high for a driving regen to manage �?usually because driving conditions prevent adequate exhaust temperatures �?the engine requests a parked regen. A parked regen runs the engine at elevated idle in a stationary vehicle with no occupants near the exhaust to complete the burn-off cycle. SPN 3055 FMI 14 is the system's formal notification that this parked regen is now required.
SPN 3055 FMI 14 is Aftertreatment Diesel Particulate Filter Condition �?a condition-exists flag (FMI 14) indicating the DPF soot load has reached the threshold requiring a forced active regen. On Cummins CM2350 ISX15/X15, the ECM monitors DPF soot load through exhaust pressure differential across the filter. Insite can display the current soot load percentage and initiate a parked regen remotely for service purposes. The driver display will show a DPF regeneration required warning and may limit vehicle speed if the regen is not initiated.
Common Symptoms
- DPF regeneration required lamp on the instrument panel
- Possible engine power reduction if the regen request is not addressed
- Reduced performance in city or stop-and-go driving where passive regen cannot occur
- Exhaust may show minor white or grey smoke at the start of a parked regen
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Extended stop-and-go or low-speed city driving preventing normal active regen during driving
- Repeated inhibition of regen requests by the driver
- Short trip operation that prevents exhaust temperatures from reaching regen conditions
- Driving conditions (elevated grade, traffic) that force frequent regen interruptions
- DPF pressure differential sensor fault causing incorrect soot load calculation
First Checks
- Follow the driver display instructions to perform a parked regen in a safe location �?the vehicle must be stationary with the parking brake engaged
- Ensure the regen area is free of flammable materials near the exhaust system
- Connect Cummins Insite to monitor soot load before and after the parked regen to confirm the cycle completed successfully
- If the parked regen fails to complete or DPF pressure remains high after regen, inspect the DPF for damage or excessive ash loading
- Check DPF pressure differential sensor function if soot load appears incorrect relative to driving history
Can I Keep Driving?
The truck is driveable but performance may be reduced. Complete the parked regen as soon as safely possible to avoid escalation to a more severe derate.
Related Codes
Related Lookup Pages
Sources
- Cummins INSITE Service Tool — Public Reference Documentation Cummins Inc. · oem · accessed 2026-06-11 · confidence medium
Source: Cummins Inc., Cummins INSITE Service Tool — Public Reference Documentation. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - QuickServe Online Cummins Inc. · oem · accessed 2026-05-05 · confidence medium
Source: Cummins Inc., QuickServe Online. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - SAE J1939 Standards Collection SAE International · official · accessed 2026-05-05 · confidence medium
Source: SAE International, SAE J1939 Standards Collection. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
How long does a Cummins ISX15 or X15 parked regen take?
A parked regen on the ISX15 or X15 typically takes 20�?5 minutes, depending on how heavily loaded the DPF is with soot. The engine will run at elevated idle throughout the process and will shut down automatically when the regen is complete. Cummins Insite can monitor the regen progress in real time, showing soot load reduction as the cycle proceeds.
Can I drive the truck while a parked regen is needed, or will it derate severely?
When SPN 3055 FMI 14 first appears, the truck is typically driveable but may have a speed or power limitation. If the parked regen is continued to be skipped, the escalation sequence increases the derate level. Completing the parked regen as soon as safely possible avoids more severe inducement and prevents DPF damage from extreme soot loading.
Is it safe to do a Cummins ISX15 parked regen inside a shop or garage?
A parked regen must be performed outdoors in a well-ventilated area, never inside a closed building or garage. The DPF exhaust during a high-temperature regen cycle can generate significant heat and exhaust gases. Position the vehicle so the exhaust outlet faces away from buildings, vehicles, and any flammable materials.