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!

Network generic / SAE

U05A4

Particulate Matter Sensor Received Invalid Data From ECM/PCM

The particulate matter (PM) sensor (smart sensor with own ECU) received implausible data from the ECM/PCM. Engine load, exhaust temperature or DPF state data needed for compensation fails plausibility checks; PM readings are degraded.

SystemNetwork
Typegeneric / SAE
GroupU0
Range / number5 / A4

Possible causes

  • ECM/PCM internal fault or sensor input drift high
  • Software version mismatch after replacement medium
  • Gateway module routing CAN messages incorrectly low

Symptoms

  • Multiple warning lights may illuminate
  • Affected modules may go into limp mode or shut down
  • Specific functions inoperative depending on module
  • Diagnostic tools may show communication faults

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 300–2500 €
  • Estimated time: 1–5 h
  • Component: pm sensor
  • Component: ecm
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

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