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P246CModerateEmissions

P246C: Diesel Particulate Filter Restriction - Forced Regeneration

2 vehicles · 2 makes · $200-$3,500 repair

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Most Reported On

2010-2015Audi A3TDI +32011-2022GMC Sierra 3500HD

P246C is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 2010-2015 Audi A3 (TDI, TDI Premium, TDI Premium Plus, TDI Prestige), and 2011-2022 GMC Sierra 3500HD, with repair costs ranging from $200 to $3,500.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (2)
  • Related Codes
  • FAQ
  • Sources (2)

Makes

  • Audi1
  • GMC1
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Common Causes

1Excessive soot buildup from too many short trips that block regeneration
2Faulty DPF differential pressure sensor or clogged sensor hoses
3Failed or incomplete regeneration cycles
4Faulty exhaust temperature sensor
5EGR system fault increasing soot production
6Fuel injector or other engine fault causing heavy soot
7Physically clogged or aging diesel particulate filter

Typical Repair Cost

$200 - $3,500

Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose P246C, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

ANCEL AD310 Classic OBD-II Scanner

by ANCEL

A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).

  • Read & clear engine codes
  • View freeze frame data
  • I/M readiness status
  • No batteries or app needed
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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

by BlueDriver

Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.

  • Enhanced diagnostics (ABS, SRS, transmission)
  • Repair Reports with verified fixes
  • Smog check readiness
  • Free app (iOS & Android)
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Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

by LAUNCH

A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.

  • Engine, transmission, ABS, SRS diagnostics
  • Live data stream & graphing
  • AutoVIN for vehicle identification
  • Free lifetime updates via Wi-Fi
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Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

by Autel

Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

  • All-system diagnostics (25+ modules)
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  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
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Vehicles Affected (2)

Audi P246C page →
A3Moderate

DPF (Diesel Particulate Filter) Clogging

2010-2015$200-$3,0001,100 reports
GMC P246C page →
Sierra 3500HDCritical

DPF (Diesel Particulate Filter) Clogging and Regeneration Failure

2011-2022$300-$3,500320 reports

Related Codes (8)

P2463Diesel Particulate Filter Restriction - Soot AccumulationP246BDiesel Particulate Filter Active/Regeneration - Incorrect Conditions/Temperature Too Low - Bank 201447EVAP System (VAG)P0401Exhaust Gas Recirculation Flow InsufficientP0402Exhaust Gas Recirculation Flow ExcessiveP0403Exhaust Gas Recirculation Circuit MalfunctionP0404Exhaust Gas Recirculation Circuit Range/PerformanceP0410Secondary Air Injection System Malfunction

FAQ

What does P246C mean?

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.

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?

Repair costs for P246C range from $200 to $3,500, depending on the vehicle and root cause.

Which vehicles are affected by P246C?

Au7o has documented P246C across 2 vehicle models from 2 manufacturers: Audi, GMC.

Sources (2)

  • resourceMyTurboDiesel - DPF/Adblue FAQ
  • ForumTDIClub - Best fuel or additive to prevent DPF clogging

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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