Powertrain, generic (extended)

P243F Particulate Filter Restriction - Soot Accumulation Too High (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P243F means the soot load estimated for the bank 2 particulate filter has climbed past the level that a normal regeneration can still handle safely. Burning off too much soot at once can overheat and crack the substrate, so many engines then block automatic regeneration and call for a service regeneration or a new filter. No manufacturer documents P243F publicly. For the bank 1 analogue P2463, GM's 2018 diesels estimate soot from the differential pressure and confirm the fault after 120 failures in 150 samples; the same GM table, oddly, labels P24A4, the J2012 bank 1 twin of P243F, as ash accumulation. Typical causes are long stretches of short trips or idling, regenerations that keep aborting and engine faults that raise soot output on that bank. Power reduction (P243B) may follow.

Likely causes

Repeatedly aborted regenerations, short trips or long idling
Engine fault raising soot output on bank 2 (injector, EGR, boost)
Pressure sensor or hose overstating the soot load

Symptoms

  • MIL and filter warning on
  • Automatic regeneration blocked, service regeneration needed
  • Reduced power possible

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,000
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

dpf b2

Related codes

P24A4P24A3P243BP243EP243A

References: gsi.ext.gm.com, law.cornell.edu.