Repeated Failed Regenerations

The car keeps starting active regenerations that never complete — rising fuel use, hot smells, a fan that runs on, and a warning that eventually stays on. Every aborted regen leaves more soot behind than a completed one removes.

What commonly causes it

  • ·Journeys ending mid-regen (the classic urban/short-run pattern)
  • ·Regen preconditions failing: low fuel, coolant temperature never reached, glow plug faults
  • ·Ash base-load so high that regens trigger constantly
  • ·On PSA/Ford FAP systems: empty Eolys additive tank silently stopping effective regeneration

Test this before blaming the DPF

  • ·Regen frequency and completion history via diagnostics — the pattern tells the story
  • ·Soot vs ash load if available
  • ·On PSA/Ford 1.6 units, additive tank level and dosing counters

Will cleaning fix it?

Yes, when the cycle is driven by accumulated ash shrinking usable capacity — cleaning resets the base load so completed regens work again. The duty-cycle side (journey pattern) still needs addressing or the interval will shorten again.

Engines this disproportionately affects

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UK

Vehicle data from the DVSA MOT history service. We confirm the exact unit on inspection. Privacy

Test evidence

Every unit is flow- and pressure-tested before and after cleaning. You get the readings, photo evidence and a completion certificate with the unit — proof for you and your customer, not marketing numbers.