DPF Soot Load High — Passive Regen Not Keeping Up
What does VOLVO-MACK-MID128-PID3719-FMI16 mean?
The VOLVO-MACK-MID128-PID3719-FMI16 (Volvo/Mack D/MP Series) diesel fault code means: DPF Soot Load High — Passive Regen Not Keeping Up. This is a moderate severity code.
Common Symptoms
- DPF lamp solid or flashing on dash
- Regen required messages
- Power loss and engine derate
- Increased fuel consumption
- Visible black smoke during acceleration
Probable Causes (Ranked by Likelihood)
- DPF heavily loaded with soot from short-trip duty cycle Very Likely
- Failed differential pressure sensor or plugged sensing hoses Likely
- Ash accumulation requires professional DPF cleaning Likely
- Failed aftertreatment fuel doser / 7th injector Possible
- DOC (oxidation catalyst) aged, reducing regen effectiveness Possible
- Broken DPF substrate (melted from uncontrolled regen) Less Likely
Step-by-Step Diagnostic Procedure
Connect Volvo PTT or Mack Guided Diagnostics and read DPF soot load estimate and differential pressure for MID128-PID3719-FMI16.
Park in a safe non-combustible area, apply parking brake, and command a parked (stationary) regen.
If regen fails or soot load is over 100%, remove DPF for professional bake + pressure wash (both soot and ash).
Inspect differential pressure sensor hoses at the DPF; replace if kinked or plugged with soot.
Verify DOC inlet temperature rises above 570 F during regen command (DOC functional check).
Inspect aftertreatment fuel doser (7th injector) for clogging; service per Volvo/Mack interval.
Frequently Asked Questions
What does Volvo/Mack code MID128-PID3719-FMI16 mean?
Volvo/Mack code MID128-PID3719-FMI16 (DPF Soot Load High — Passive Regen Not Keeping Up) is a moderate-severity diagnostic trouble code set on D11/MP7, D13/MP8, and D16/MP10 diesel engines in Volvo VNL/VNR and Mack Anthem/Pinnacle/Granite/Titan trucks. It indicates a fault in the DPF system and should be read with Volvo Premium Tech Tool (PTT) or Mack Guided Diagnostics.
Can I drive a Volvo or Mack truck with code MID128-PID3719-FMI16?
Limited short-term operation is usually possible, but the fault will illuminate the Check Engine Light and should be diagnosed promptly to avoid cascading aftertreatment or fueling faults.
How much does it cost to fix Volvo/Mack code MID128-PID3719-FMI16?
Typical repair falls in the range $700-$4,500. Sensor/wiring repairs are at the low end; EGR cooler, NOx sensor set, DEF pump, injector, or head work runs at the high end. Volvo PTT or Mack Guided Diagnostics is normally required for calibration and parameter programming.