P2458Diesel Particulate Filter Regeneration Duration
- 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
- During a regeneration the engine raises exhaust temperature, mostly by late post-injection burned in the oxidation catalyst, until the soot in the particulate filter oxidises. P2458 means a regeneration took longer than the calibrated limit, so the filter was not cleaned in the expected time. CARB asks diesel OBD to detect regenerations that do not complete as intended. On the Opel/GM 2.0 CDTi in the Saab 9-5 (2010) the ECM runs the check with coolant at 73 to 96 °C and sets the code when regeneration times are too long; it is a Type C code there, stored without the MIL. Volkswagen saw P2458 with the MIL on 2011 Jetta and Golf 2.0 TDI (CJAA) and fixed it with an ECM software update, so the calibration is worth checking before parts are replaced. Otherwise the regeneration is slowed by low exhaust temperature, a weak oxidation catalyst, faulty temperature or pressure readings, or trips too short to finish. P2459 covers regenerations that happen too often.
- What you may notice
- DPF warning or MIL, depending on the manufacturer
- Cooling fan and raised idle running on after shutdown
- Higher fuel consumption
- Likely causes
- PossibleECM calibration that needs an update (documented by Volkswagen)
- PossibleShort trips that keep regenerations from finishing
- RareOxidation catalyst too weak to reach regeneration temperature
- 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: €0 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.