P246B

Vehicle Conditions Incorrect for Particulate Filter Regeneration

Q: Is it safe to drive with P246B?

Yes for now, but the filter keeps loading with soot. Complete a longer highway drive and get it diagnosed before it forces a limp mode or a costly forced regen.

Q: Can I just clear P246B?

Clearing it won't help — until the conditions blocking regeneration are corrected, the ECM will set it again and soot will keep accumulating.

Auxiliary emissions (DPF) Generic OBD-II Medium

What it means

P246B means the ECM wanted to regenerate (burn off soot from) the diesel particulate filter but the operating conditions weren't right to do it — often exhaust temperature, driving pattern, fuel level, or a sensor fault. Nothing burns off, so soot keeps accumulating until conditions or the underlying fault are corrected.

Medium

Can I keep driving? Drivable, but the DPF can't complete a regeneration under current conditions — keep soot from building up by completing a longer highway drive and diagnosing soon.

Real-world scan data

Seen in

154

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Appears alongside · share of P246B scans

P2463in 64.9% 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

Check-engine light on
DPF or exhaust warning light and 'regeneration not possible' messages
Regeneration cycles that start but never complete
Reduced power or limp mode if soot load climbs too high

Common causes

Most likely first

Frequent short/low-speed trips that never allow regeneration to finishLikely
Faulty exhaust gas temperature sensor keeping exhaust temps out of rangeCommon
EGR, turbo, or boost fault preventing the required conditionsCommon
Low fuel level or coolant temperature below the regen thresholdLess often
Faulty DPF pressure sensor giving the ECM a wrong soot estimateLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and pull any companion EGT, EGR, or DPF codes first.
Take the car for a sustained highway drive so a regeneration can complete.
Check exhaust gas temperature sensors and DPF pressure sensor readings.
Confirm adequate fuel level and normal coolant operating temperature.
Repair any underlying fault, then command a forced regeneration with a capable scan tool.

FAQ

Quick answers

Is it safe to drive with P246B?+

Yes for now, but the filter keeps loading with soot. Complete a longer highway drive and get it diagnosed before it forces a limp mode or a costly forced regen.

Can I just clear P246B?+

Clearing it won't help — until the conditions blocking regeneration are corrected, the ECM will set it again and soot will keep accumulating.

Read & clear P246B yourself

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

▶ Get it on Google Play

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