P179C: Diesel Particulate Filter Restriction - Ash Accumulation
2 vehicles · 2 makes · $300-$4,500 repair
Most Reported On
P179C is an OBD-II diagnostic trouble code meaning “Diesel Particulate Filter Restriction - Ash Accumulation.” The DPF has excessive ash buildup that cannot be removed by regeneration. Ash is a byproduct of oil consumption and accumulates over time. This code is most commonly reported on 2017-2025 Volkswagen Golf R (MK7.5 R (DSG), MK8 R (DSG)), and 2019-2024 Audi SQ2 (7-speed S tronic), with repair costs ranging from $300 to $4,500.
Common Causes
Typical Repair Cost
Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P179C, you'll need an OBD-II scanner. Here are our recommendations at every price point.
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
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)
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
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)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
FAQ
What does P179C mean?
P179C stands for "Diesel Particulate Filter Restriction - Ash Accumulation." The DPF has excessive ash buildup that cannot be removed by regeneration. Ash is a byproduct of oil consumption and accumulates over time.
What are the most common causes of P179C?
The most common causes of P179C are: Normal ash accumulation over high mileage, Excessive oil consumption, Wrong oil specification, DPF approaching end of service life, Failed regeneration cycles. The specific cause varies by vehicle.
How much does it cost to fix P179C?
Repair costs for P179C range from $300 to $4,500, depending on the vehicle and root cause.
Which vehicles are affected by P179C?
Au7o has documented P179C across 2 vehicle models from 2 manufacturers: Audi, Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.