International A26 SPN 3055 FMI 14 �?DPF Condition (Parked Regeneration Required)

Code Details

Plain-English Meaning

The International A26 engine is the Navistar in-house diesel used in International LT Series, RH Series, and HX Series trucks. When stop-and-go or short-haul operation prevents the exhaust from staying hot enough for an active driving regen, soot accumulates in the DPF and triggers SPN 3055 FMI 14. The driver must perform a parked regen in a safe outdoor area away from flammable materials and with good ventilation. SPN 3055 FMI 14 is part of the A26's standard SCR/DPF emissions management sequence. If the driver-initiated parked regen fails to start, a blocking condition may be present — these include low fuel level, an active cooling system fault, or an active DEF quality fault. ServiceMaxx identifies and allows resolution of blocking conditions before the regen can be forced. The A26 uses the Diamond Logic body builder interface, so fleet vehicles with body-mounted PTO systems can be in a state that also inhibits regen initiation.

SPN 3055 FMI 14 is DPF Condition �?parked regen required. ServiceMaxx (Navistar's OEM diagnostic tool) and JPRO display DPF soot load and regen history for the A26. ServiceMaxx can initiate a forced stationary regen for service purposes.

Common Symptoms

• Amber DPF regen warning on the International LT or RH Series instrument cluster
• Progressive power derate will escalate if the parked regen is not performed
• More frequent on city delivery, construction, or refuse routes with heavy stop-and-go
• Driver may notice the regen icon appearing more frequently before the full SPN 3055 FMI 14 fault is set
• Low exhaust idle sound during a normal driving regen attempt (regen is trying but cannot sustain)

Possible Causes

Possible causes may include the items below. The list is not a parts diagnosis.

• Duty cycle with insufficient driving regen opportunity — stop-and-go, short haul, or frequent idling
• Driver inhibiting regen during operation — inhibit switch on or regen not acknowledged
• Short-trip routes without sustained exhaust temperature for passive or active regen
• Active DPF inlet temperature sensor fault preventing regen from initiating
• Extended operation at low-load idle (yard moves, staging) preventing soot burnoff

First Checks

• Perform a parked regen using the International LT or RH Series driver display sequence — the truck must be outdoors, engine warm, and in a well-ventilated area away from flammables
• Connect ServiceMaxx before the regen to check for blocking conditions that would prevent the regen from starting
• Monitor DPF soot load in ServiceMaxx during the regen to confirm the filter is actively burning soot
• After the regen completes, confirm that soot load returned to a normal level using ServiceMaxx DPF status data
• If parked regen completes but SPN 3055 FMI 14 returns within a short time, evaluate the duty cycle — a chronic short-trip route may require a DPF cleaning service interval adjustment

Can I Keep Driving?

Driveable but derate will escalate. Complete regen as soon as safely possible.

Related Lookup Pages

• FMI 14 explanation
• Aftertreatment fault codes
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