P2002 on Audi: How to Diagnose & Fix
Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
3 Audi models · 3 documented issues · $200-$3,000 repair
P2002 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)
The A1 is sold mainly as a town/city car, so diesel (1.6 TDI / 2.0 TDI) owners doing short, stop-start journeys never get the diesel particulate filter hot enough for passive regeneration. The DPF clogs with soot, and a faulty/sticking EGR valve accelerates this by raising soot output. Failed active regens can also dilute the engine oil with diesel. A blocked DPF triggers limp mode and is expensive to replace.
Common Symptoms
- DPF / glow-plug warning light
- Reduced power / limp mode
- Increased fuel consumption
- Rising engine oil level (fuel dilution)
- Frequent regeneration cycles
How to Fix
Take the car on a sustained motorway run (~2,000+ rpm for 15-20 minutes) to force regeneration when the warning first appears. Clean or replace a faulty EGR valve, use the correct low-ash (504/507) oil, and forced/professional DPF cleaning if heavily blocked; replace the DPF if soot load is beyond recovery. Check oil level isn't rising from fuel dilution.
Sources for this issue (1)
Q2 TDI diesels (1.6 TDI / 2.0 TDI) suffer from DPF clogging when the car is mostly used for short, low-speed urban journeys. The soot filter never reaches the exhaust temperature needed to complete a passive/active regeneration, so soot accumulates, the DPF warning light comes on, and the car may enter a forced-regen cycle or limp mode. Repeated interrupted regens (driver slowing/stopping before the cycle finishes) make it worse and can dilute engine oil with diesel.
Common Symptoms
- DPF / exhaust-emissions warning light on
- Reduced power / limp mode
- Frequent regenerations, increased fuel use
- Rising engine oil level (diesel dilution)
How to Fix
Drive at a steady speed (>60 km/h / ~40 mph) under moderate load for 15–30 minutes to allow regeneration to complete; if blocked, the dealer performs a forced/static regeneration with diagnostic equipment. Severely blocked filters need professional DPF cleaning or replacement. Long-term: avoid exclusively short trips.
Sources for this issue (1)
P2002 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 P2002 mean on a Audi?
P2002 stands for "Diesel Particulate Filter Efficiency Below Threshold (Bank 1)." P2002 indicates that the diesel particulate filter (DPF) on bank 1 is performing below its required efficiency threshold. The DPF captures and stores soot from diesel exhaust and periodically burns it off (regeneration); the engine computer monitors exhaust pressure across the filter and other data to judge how well it's trapping and clearing soot. When that efficiency falls too low, this code sets. Symptoms can include reduced power, a clogged-filter warning, frequent or failed regenerations, and increased emissions. On Audi it is documented across 3 models: A3, A1, Q2.
What are the most common causes of P2002?
The most common causes of P2002 are: Clogged or damaged diesel particulate filter, Failed or incomplete DPF regeneration (mostly short trips), Faulty differential (DPF) pressure sensor or hoses, Faulty exhaust temperature sensor(s), Exhaust leak before or across the DPF, Engine running issues causing excess soot (injectors, EGR, turbo), Use of incorrect (non-low-ash) engine oil or fuel quality issues. The specific cause varies by vehicle.
How much does it cost to fix P2002 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 P2002 on a different make?
View P2002 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.