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

P24C9

Particulate Matter Sensor Temperature Circuit High

Same as P24C6 with the signal voltage above the plausible range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / C9

Possible causes

  • Signal shorted to supply high
  • Connector pins corroded - high contact resistance low
  • Supply wire pinched against B+ source low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 400–1200 €
  • Estimated time: 1–3 h
  • Component: particulate matter sensor
  • MIL / check engine light
  • emissions-relevant

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