P2002: How to Diagnose & Fix — Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
57 vehicles · 19 makes · $50-$12,000 repair
How to diagnose and fix P2002: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Land Rover Discovery · 2010–2020
Diesel Discovery models suffer from DPF regeneration problems, especially when used for short journeys. The DPF becomes overloaded with soot and the active regeneration cycle cannot complete, leading to a blocked filter. Warning lights illuminate and the engine enters limp mode. Repeated failed regenerations cause the DPF to become permanently blocked, requiring expensive replacement.
Common Symptoms
- DPF warning light on dashboard
- Reduced engine power / limp mode
- Increased fuel consumption during regen attempt
- Hot exhaust smell
- Engine fan running at high speed
- Rough idle
How to Fix
Perform a forced DPF regeneration using JLR diagnostic equipment. If the DPF is heavily loaded but not damaged, a professional chemical clean can restore it. Replace the DPF if it is beyond cleaning. Prevent future issues by taking the vehicle on regular extended highway drives to allow passive regeneration.
Owner tips & cautions
- WarningIf you only do short trips, a diesel Discovery is the wrong vehicle. The DPF needs at least 20 minutes of highway driving weekly to stay clean.
Mercedes-Benz Sprinter · 2014–2025
The Sprinter diesel exhaust fluid (DEF/AdBlue) selective catalytic reduction system is plagued by faults in the dosing module, NOx sensors, DEF heater, and SCR catalyst. Failures trigger the dreaded "engine derate" countdown that limits vehicle speed to 5 mph if not resolved, stranding commercial vehicles. The system is sensitive to DEF quality and cold weather.
Common Symptoms
- Check engine light with SCR fault codes
- Engine derate countdown warning on dashboard
- Vehicle limited to 5 mph (derated)
- DEF warning light illuminated
- Higher fuel consumption
How to Fix
Diagnose the specific failed component with Star Diagnostics — the system has multiple failure points. Common repairs include the DEF dosing module, NOx sensors, DEF heater element, and DEF quality sensor. Use only ISO 22241-certified DEF fluid. A full SCR reset with Star Diagnostics is required after component replacement.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- PEAK BlueDEF ISO 22241 diesel exhaust fluid, 2.5 gallonsOEMPEAK DEF002 / ISO 22241-1
Low-level refill or drain/refill after testing confirms the DEF itself is low, contaminated or out of specification Fitment/availability: The inspected direct U.S.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- WarningNever use non-certified DEF fluid. Cheap DEF causes crystallization in the dosing module and destroys the SCR catalyst. Buy from reputable suppliers only. BlueDEF from Peak is widely recommended.
Land Rover Range Rover Sport · 2014–2022
The diesel Range Rover Sport suffers from DPF clogging when used predominantly for short trips. The DPF regeneration cycle requires sustained exhaust temperatures that are not achieved in city driving. The vehicle may attempt regeneration frequently, increasing fuel consumption and causing a diesel smell. If regeneration fails repeatedly, the DPF becomes permanently blocked.
Common Symptoms
- DPF warning light
- Increased fuel consumption
- Diesel smell from exhaust
- Reduced engine power
- Engine fan running at high speed during regen
- Limp mode
How to Fix
Take the vehicle for a 30+ minute highway drive weekly to allow passive DPF regeneration. If the DPF warning light is on, a dealer can perform a forced regeneration. For severely blocked DPFs, professional cleaning or replacement is needed. Consider fuel additives that lower the soot ignition temperature.
Owner tips & cautions
- WarningA diesel Range Rover Sport is the wrong choice if your daily commute is under 10 miles. The DPF will clog within a year.
Jaguar XF · 2009–2018
Audi A3 · 2010–2015
Find P2002 by make
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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?
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.
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?
Repair costs for P2002 range from $50 to $12,000, depending on the vehicle and root cause.
Which vehicles are affected by P2002?
Au7o has documented P2002 across 57 vehicle models from 19 manufacturers: Audi, Chevrolet, Citroen, Ford, GMC, Hyundai, Jaguar, Land Rover, Mazda, Mercedes-Benz, Opel, Peugeot, Porsche, Renault, SEAT, Skoda, Suzuki, Volkswagen, Volvo.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.