Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
The P2002 code means the vehicle's onboard diagnostic system has detected: Diesel Particulate Filter Efficiency Below Threshold (Bank 1). This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $1,000 - $3,500 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Reduced engine power or limp mode
- Excessive black smoke from exhaust
- Frequent DPF regeneration attempts
- Poor fuel economy
Probable Causes (Ranked by Likelihood)
- Clogged or damaged diesel particulate filter Very High
- Failed DPF regeneration due to short trips High
- Faulty DPF differential pressure sensor Moderate
- Exhaust leak before DPF Moderate
- Turbocharger oil leak contaminating DPF Low
Frequently Asked Questions
What does P2002 mean?
P2002 indicates the diesel particulate filter on Bank 1 is not trapping soot particles efficiently, often because the filter is clogged or damaged beyond regeneration capability.
Can I drive with a P2002 code?
You can drive short distances, but the vehicle may enter limp mode. Continued driving with a clogged DPF can cause turbo damage and expensive repairs.
How much does it cost to fix P2002?
A forced regeneration may cost $100-$300. DPF cleaning runs $300-$600. Full DPF replacement costs $1,500-$3,500 depending on the vehicle.
What actually makes the computer set this particulate filter code?
California's OBD II regulation requires the system to flag a PM trap before its capability drops enough to push emissions past 1.5 times the applicable standards (Title 13 CCR 1968.2, section (e)(15.2)). Note the scope: that criterion is written for diesel passenger cars, light-duty trucks and medium-duty passenger vehicles certified to a chassis dynamometer standard. Heavy-duty engines are governed by a separate regulation, so a filter code on a big truck is not set by this rule. This is the threshold the monitor is designed around, not a description of your specific fault — the regulation says what the system must detect, not how to find it on your vehicle.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
-
Read freeze frame data and note DPF soot loading percentage
-
Check DPF differential pressure sensor readings at idle and under load
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Attempt a forced DPF regeneration with scan tool
-
Inspect DPF for physical damage, cracks, or excessive soot loading
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- California Code of Regulations, Title 13 section 1968.2 (OBD II)malfunction criteria, section (e)
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
P2002 on Diesel, EV & Equipment
The same code ID appears across other engines and platforms. The diagnostic flow varies by manufacturer — these are the platform-specific breakdowns:
Commonly Affected Vehicles
- 2011-2019 Ford F-250 6.7L Power Stroke
- 2013-2020 Ram 2500 6.7L Cummins
- 2011-2019 Chevrolet Silverado 2500 6.6L Duramax
- 2009-2015 Volkswagen Jetta 2.0L TDI
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