P24FCParticulate Matter Sensor Heater Control Circuit Driver Current/Temperature Too High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24FC concerns the output stage that powers the heater of the particulate matter sensor: the driver reports excessive current or an internal temperature past its limit, which suggests a heater with shorted turns or too little resistance, or an overheating sensor electronics unit. On heavy trucks this sensor works as a self-diagnosing device after the SCR catalyst and reports over J1939. Volvo and Mack list P24FC00 in two editions of their PM sensor diagnosis guide for US14+OBD16 engines onward among the codes that justify replacing the sensor, whereas supply-voltage and communication codes point elsewhere. No public threshold exists. P24B5/P24B6 are plain heater circuit shorts, P24B7 the heater resistance. A sensor that cannot heat cannot burn off soot, so filter monitoring stops.
- What you may notice
- Warning lamp
- No soot reading from the PM sensor, DPF monitoring not completed
- Likely causes
- LikelyInternal failure of the smart PM sensor (heater or electronics)
- PossibleWater ingress cracking the ceramic element or shorting the heater
- RareUnusually high exhaust temperature at the sensor, e.g. during repeated regenerations
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €250 – €1,100
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.