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P2459

Particulate Filter Regeneration Frequency Bank 1

Auxiliary emissions / diesel particulate filter Generic OBD-II Medium

What it means

P2459 means the ECM sees the diesel particulate filter regenerating too often — the intervals between soot burn-off cycles are shorter than expected. It usually points to excess soot loading, short-trip driving that never completes a regen, or a pressure sensor reading the filter wrong. The engine still runs, but fuel economy suffers and the filter should be checked.

Medium

Can I keep driving? Usually drivable, but the filter is regenerating abnormally often — address it to protect fuel economy and the DPF.

Real-world scan data

Seen in
667
scans in the past year
Found in
0.1%
of scans
0.2%
of scans that found faults

Appears alongside · share of P2459 scans

P0645in 34.3% of scans
P242Fin 20.7% of scans
P243Cin 11.1% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Common causes

Most likely first

  1. Frequent short-trip or low-speed driving that prevents a complete regeneration
  2. Excess soot loading from injector, EGR, or combustion problems
  3. Faulty DPF differential-pressure sensor giving false soot readings
  4. DPF nearing the end of its service life
  5. Poor-quality or high-sulfur fuel

How to diagnose & fix

Work through it in order

  1. Take a sustained highway drive to let the filter complete a full regeneration.
  2. Scan for related DPF pressure and EGT codes that point to the real cause.
  3. Check the DPF differential-pressure sensor and its hoses for accuracy.
  4. Inspect for injector or EGR faults that overload the filter with soot.
  5. If soot load stays high, perform a forced regeneration; replace the DPF only if it is at end of life.

FAQ

Quick answers

Is it safe to drive with P2459?+
Short-term yes, but frequent regenerations dilute engine oil and waste fuel. Have the cause found before the filter clogs.
Can I just clear P2459?+
It will return once the ECM logs more abnormal regen cycles. Fix the underlying soot or sensor issue instead.

Related codes

Read & clear P2459 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

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Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX