Powertrain, generic (extended)

P24A0 Closed Loop Particulate Filter Regeneration Control At Limit - Temperature Too Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P24A0 means the regeneration temperature loop is already giving all the extra heat it may, yet the gas ahead of the particulate filter stays below target. GM describes it as an HC injector control deviation: the gap between setpoint and measured temperature ahead of the DPF is watched while the filter warms up, and 10 failing out of 20 samples set a Type B fault; the 2014 table phrases it as insufficient hydrocarbon injector authority. Ford's 2023 summary uses P24A0 when the controller sits at a clip and the temperature error stays large long enough. Volvo truck bulletin K86412082 lists it with P249F. Likely culprits are a restricted HC doser or fuel supply, an aged oxidation catalyst that lights off poorly, or a faulty temperature sensor. Soot may build up because regenerations stay incomplete.

Likely causes

Hydrocarbon dosing valve or its fuel supply restricted
Oxidation catalyst aged or face-plugged, so the fuel does not burn ahead of the filter
Exhaust temperature sensor reading too low
Exhaust leak ahead of the sensors cooling the gas

Symptoms

  • Malfunction indicator lamp on
  • Regenerations take long or do not finish
  • Soot load codes may follow

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time1–4 h

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

Parts involved

dpf b1

Related codes

P24A1P249FP244CP24A2

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, static.nhtsa.gov.