P24A4Particulate Filter Restriction - Soot Accumulation Too High (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24A4 marks the critical stage for the bank 1 filter: the soot load is so high that a normal regeneration risks overheating and cracking the substrate. Deutz names P24A4-00 a critical soot load. GM's 2016 and 2018 diesel tables use P24A4 for a clogged filter that has to be replaced, judged from the filtered flow resistance derived from differential pressure, 5 failures in 10 samples, Type A with one trip; the 2018 table labels the line ash accumulation, so GM appears to use the code for a load no regeneration can remove. P2463 is the earlier soot warning, P242F the separate ash code. Many engines then reduce power and block automatic regeneration, so only a controlled service regeneration, cleaning or a new filter will help.
- What you may notice
- Marked loss of power, limp mode
- Automatic regeneration no longer runs
- Malfunction indicator and filter warning lamp on
- Likely causes
- LikelyEarlier soot warnings or failed regenerations not dealt with
- PossibleExcess soot from injectors, EGR valve or turbocharger faults
- PossibleFilter saturated with ash at end of service life
- RareDifferential pressure measurement reading falsely high
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.