Code Details
| Display code | SPN 3246 FMI 0 |
|---|---|
| SPN | 3246 |
| FMI | 0 |
| OEM code | None listed |
| Manufacturer | PACCAR |
| System | Aftertreatment �?DPF |
| Component | DPF / DPF outlet temperature sensor / regen system |
| Source address | Unknown or not applicable |
| Severity | medium |
| Review status | source backed |
| Source confidence | medium |
| Last reviewed | 2026-06-12 |
Plain-English Meaning
During active DPF regeneration on the PACCAR MX-13, the DPF temperature rises to burn off accumulated soot. SPN 3246 FMI 0 means the post-DPF temperature exceeded the normal operating ceiling. On Kenworth T680, T880, and Peterbilt 579 trucks with the MX-13, this is most commonly seen when the DPF has been allowed to load heavily before a regen is completed, resulting in a more intense and hotter burn cycle.
SPN 3246 FMI 0 is DPF Outlet Temperature above normal. DAVIE4 and PACCAR ESA provide aftertreatment temperature live data including DPF inlet and outlet temperatures, and store fault event snapshots showing peak temperatures during each regen cycle. Comparing DPF inlet versus outlet temperature during a monitored regen distinguishes a normal high-intensity regen from abnormal heat concentration in the downstream portion of the filter.
Common Symptoms
- Fault set during or after active regen
- MX-13 may interrupt or limit a regen cycle if temperatures exceed safety thresholds
- High exhaust temperature indicator on the dash
- May accompany high soot load codes
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- DPF heavily loaded with soot from missed or inhibited regen cycles
- Rich combustion event sending excess hydrocarbons to the aftertreatment
- Repeated inhibited regens resulting in an unusually intense catch-up regen
- DPF outlet temperature sensor fault
- DPF loaded with ash (requires service cleaning)
First Checks
- Connect DAVIE4 or PACCAR ESA and review DPF soot load and regen event history
- Monitor DPF inlet and outlet temperatures during a regen to identify abnormal heat profiles
- Check for companion fuel system codes that could indicate over-fueling
- Review regen inhibition history to determine if regens were being blocked by operating conditions or driver action
- Confirm DPF ash load �?an ash-loaded filter should be cleaned or replaced
Can I Keep Driving?
Typically driveable. Repeated DPF outlet over-temperatures can shorten DPF and SCR catalyst service life. Identify and address the root cause.
Related Codes
Related Lookup Pages
Sources
- PACCAR / Kenworth / Peterbilt Service Support — MX Engine Resources PACCAR Inc. · oem · accessed 2026-06-11 · confidence medium
Source: PACCAR Inc., PACCAR / Kenworth / Peterbilt Service Support — MX Engine Resources. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - PACCAR Engine Technical Services PACCAR Inc. · oem · accessed 2026-06-10 · confidence medium
Source: PACCAR Inc., PACCAR Engine Technical Services. 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
Should I be concerned if my Kenworth T680 MX-13 shows SPN 3246 only once?
A single occurrence after an unusually long period without a complete regen �?such as extended city driving that never allowed the DPF to regen �?is less concerning than repeated occurrences. Use DAVIE4 to check the DPF soot load history and regen frequency. If the regen completed and soot load returned to normal, continued operation with monitoring is typical.
Does PACCAR ESA show the peak DPF temperature during a regen event?
Yes. PACCAR ESA and DAVIE4 store fault event snapshots that include peak temperatures recorded at the time of the fault. The aftertreatment temperature live data view also shows current inlet and outlet temperatures during a monitored regen session.
How do I know when the PACCAR MX-13 DPF needs ash cleaning?
Ash cannot be burned off during a normal DPF regen �?it accumulates over time regardless of regen frequency. DAVIE4 tracks the estimated ash load level. When ash accumulation reaches the service interval, the DPF must be removed for professional cleaning (forced air or aqueous washing). Typical ash cleaning intervals on the MX-13 are specified in the engine maintenance schedule.