Powertrain, generic (extended)

P2002 Diesel Particulate Filter Efficiency Below Threshold (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2002 means the particulate filter on bank 1 lets too much soot through, typically because the substrate is cracked, partly melted, emptied or bypassed. CARB requires diesel OBD to flag a filter whose filtering performance lets PM emissions exceed the limit. Older systems judge this from the pressure drop: GM's 2009 Duramax compares the flow resistance shortly after a regeneration (within 600 s or 18.6 miles, soot load at most 40 g) with a table and aims at a filter leaking eight times the standard. Newer systems use a resistive PM sensor behind the filter: on the 2014 Cruze 2.0 diesel, GM's 2018 diesel group and Ford's 2023 diesels the code sets when the sensor current exceeds 12 µA before the modelled amount of soot needed to trigger an intact sensor has passed. Ford names cracked substrates on Transit 3.2, F-150 3.0 and Super Duty 6.7 and replaces the filter; GM states that a filter with P2002 cannot be cleaned by service regeneration. Regenerating does not cure it.

Likely causes

Filter substrate cracked or melted, often after an uncontrolled regeneration
Filter removed, emptied or bypassed
Faulty differential pressure sensor or leaking sensor hoses on pressure-based systems

Symptoms

  • Malfunction indicator lamp on
  • Usually no change in driveability
  • Visible soot at the tailpipe in severe cases

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–3,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

What to check first

  1. Check differential pressure readings
  2. Inspect sensor pipes
  3. Inspect the DPF

Parts involved

diesel particulate filterparticulate matter sensordpf differential pressure sensor

Related codes

P2003P2463P2453P24AF

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.