OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P244A

Diesel Particulate Filter Differential Pressure Too Low

The differential pressure across the DPF is below the calibrated minimum even at higher loads. Often a sign of a damaged or missing filter substrate, or a leak in the sensing line.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / 4A

Possible causes

  • Cracked or missing DPF substrate high
  • Leak in pressure sensing line medium

Symptoms

  • Check engine light or DPF warning light on
  • Power loss / limp mode
  • Increased fuel consumption
  • Failed forced regeneration attempts

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 400–3000 €
  • Estimated time: 1.5–6 h
  • Component: diesel particulate filter
  • Component: dpf diff pressure sensor
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required
  • limp mode possible

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication