P246B on 2012-2015 Volkswagen Passat — Diesel Particulate Filter Active/Regeneration - Incorrect Conditions/Temperature Too Low - Bank 2
1 vehicles · 1 makes · $300-$3,000 repair
How to diagnose and fix P246B: most-reported vehicles
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Volkswagen Passat · 2012–2015
The diesel particulate filter (DPF) in TDI Passat models is prone to clogging, particularly in vehicles used primarily for short trips or city driving where the exhaust does not get hot enough for passive regeneration. A clogged DPF triggers regeneration cycles that increase fuel consumption and can eventually put the vehicle in limp mode if the filter becomes too saturated with soot.
Common Symptoms
- DPF warning light on dash
- Reduced power / limp mode
- Increased fuel consumption
- Frequent short regeneration cycles
- Strong exhaust smell during regen
How to Fix
Perform a forced DPF regeneration using VCDS or an OBD-II tool capable of commanding active regen. If the filter is heavily clogged, professional DPF cleaning services can restore it. In extreme cases, DPF replacement is necessary. Prevent future issues by taking the vehicle on highway drives of 20+ minutes regularly to allow passive regeneration. Use low-ash diesel oil (VW 507.00 spec).
Sources for this issue (1)
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P246B 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 P246B mean?
P246B stands for "Diesel Particulate Filter Active/Regeneration - Incorrect Conditions/Temperature Too Low - Bank 2." This code indicates the engine computer detected that conditions were not correct to perform a proper regeneration (burn-off) cycle of the diesel particulate filter (DPF) on bank 2, typically because exhaust temperatures were too low. The DPF traps soot from diesel exhaust and must periodically heat up to roughly 600 C to burn that soot away. When the computer sees inconsistent temperature or sensor data over several drive cycles, it logs this code to warn that the filter cannot clean itself safely. Left unaddressed, the DPF can become clogged and restrict the exhaust.
What are the most common causes of P246B?
The most common causes of P246B are: Short trips / low-speed driving preventing regeneration, Faulty exhaust gas temperature (EGT) sensor, Clogged or aged diesel particulate filter, Faulty DPF differential pressure sensor, Excess soot from a running engine fault (air leak, injector issue), Failed or aborted regeneration cycles, Wiring or connector faults on EGT sensors. The specific cause varies by vehicle.
How much does it cost to fix P246B?
Repair costs for P246B range from $300 to $3,000, depending on the vehicle and root cause.
Which vehicles are affected by P246B?
Au7o has documented P246B across 1 vehicle models from 1 manufacturers: Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.