P2003Diesel Particulate Filter Efficiency Below Threshold (Bank 2)
- 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
- P2003 is set when the particulate filter of bank 2 lets too much soot slip through, which almost always points to a cracked, partly melted, hollowed-out or bypassed core. Separate filters per bank are uncommon, so the code is rare. No manufacturer documents P2003 publicly; GM and Ford explain the detection under the bank 1 code P2002: older systems judge the flow resistance of a freshly regenerated filter, newer ones use a resistive PM sensor behind it, which signals too early when soot gets past the filter. CARB requires the system to catch a filter whose leakage pushes PM beyond the limit and also one whose substrate is missing. A forced regeneration will not cure a broken filter; it has to be replaced. The warning lamp may be the only sign, with soot at the tailpipe if the leak is large.
- What you may notice
- Malfunction indicator lamp on
- Visible soot at the tailpipe with a large leak
- Engine performance normally unaffected
- Likely causes
- LikelyBank 2 filter core cracked or melted after an overheated regeneration
- PossibleFilter on bank 2 removed, emptied or bypassed
- RarePM sensor or differential pressure measurement on bank 2 giving false values
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.