Powertrain, generic (extended)

P2458 Diesel Particulate Filter Regeneration Duration

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

ECM calibration that needs an update (documented by Volkswagen)
Short trips that keep regenerations from finishing
Oxidation catalyst too weak to reach regeneration temperature

Symptoms

  • DPF warning or MIL, depending on the manufacturer
  • Cooling fan and raised idle running on after shutdown
  • Higher fuel consumption

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,500
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

diesel particulate filterdiesel oxidation catalystexhaust gas temperature sensordpf differential pressure sensorecm

Related codes

P2459P2463P2002P24A2

References: law.cornell.edu, saabwisonline.com, static.nhtsa.gov.