OBD-II · Engine and powertrain (P)
P2458
DPF regeneration duration bank 1
What it means
A DPF regeneration (burning off soot at high exhaust temperature) took longer than allowed or did not complete.
Symptoms
- DPF warning light and/or engine warning light
- cooling fan running after switch-off, higher idle
- possibly reduced power
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | regeneration repeatedly interrupted by short trips or stopping the engine |
| 02 | exhaust gas temperature sensor fault |
| 03 | oxidation catalyst (DOC) not heating up because it is aged or contaminated |
| 04 | engine running too cold (thermostat stuck open) |
| 05 | DPF heavily loaded with soot or ash |
What to check, step by step
- 01Read other stored codes and fix sensor faults first.
- 02Check coolant temperature reaches normal operating temperature (thermostat).
- 03Read soot/ash load and regeneration history.
- 04Before a workshop regeneration, confirm soot load is below the OEM limit, oil level and condition are acceptable, and all prerequisites are met. Follow the guided procedure with fire precautions and monitor exhaust temperatures against OEM targets.
- 05If temperatures do not rise, suspect the oxidation catalyst or post-injection.