P246C on Audi: How to Diagnose & Fix
Diesel Particulate Filter Restriction - Forced Regeneration
1 Audi model · 1 documented issue · $200-$3,000 repair
P246C on Audi by model: symptoms, diagnosis and fix
The DPF can become clogged, especially with city driving and short trips that don't allow for proper regeneration cycles. This is more common after the emissions fix was applied. A clogged DPF causes reduced power and warning lights. OEM DPF assembly part numbers: 1K0254706LX (earlier production) and 1K0254708GX (later production). Fits 2009-2014 Audi A3 TDI with CBEA/CJAA engines. DPF differential pressure sensor: available from KermaTDI for CJAA/CKRA engines.
Common Symptoms
- DPF warning light
- Reduced power (limp mode)
- Increased fuel consumption during regen
- Strong exhaust smell during regen
- Check engine light with DPF codes
How to Fix
Allow DPF regeneration by driving at highway speeds (65+ MPH) for 15-20 minutes regularly. For forced regen via VCDS: go to adaptation, enter security code 12233, change channel 18 from 0 to 1 while maintaining highway speed. Monitor soot levels via VCDS (Particle Filter Carbon Mass). If severely clogged, professional DPF cleaning with Liqui Moly 20110 DPF Cleaning Fluid (used with 20112 DPF Cleaning Flush and 7945/7946 spray tools) can help. Note: cleaning removes soot only, not ash - ash accumulation requires DPF replacement. OEM replacement DPF often back-ordered for weeks.
Sources for this issue (1)
P246C code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P246C mean on a Audi?
P246C stands for "Diesel Particulate Filter Restriction - Forced Regeneration." This diesel emissions code sets when the engine control module detects that the diesel particulate filter (DPF) is heavily restricted with trapped soot, to the point that normal cleaning cycles have not kept up. The DPF captures soot from the exhaust and periodically burns it off in a process called regeneration; when soot load gets too high, the system flags this code and often calls for a forced regeneration or reduces engine power to protect the filter and engine. It generally indicates the filter is clogged and that something has been preventing successful regeneration. Ignoring it can lead to limited power (limp mode) and eventual filter damage. On Audi it is documented across 1 model: A3.
What are the most common causes of P246C?
The most common causes of P246C are: Excessive soot buildup from too many short trips that block regeneration, Faulty DPF differential pressure sensor or clogged sensor hoses, Failed or incomplete regeneration cycles, Faulty exhaust temperature sensor, EGR system fault increasing soot production, Fuel injector or other engine fault causing heavy soot, Physically clogged or aging diesel particulate filter. The specific cause varies by vehicle.
How much does it cost to fix P246C on a Audi?
Published repair estimates on Audi range from $200 to $3,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P246C on a different make?
View P246C across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.