P2002 code meaning
Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
Powertrain system Generic code P20xx codes Check engine light
What P2002 means
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.
P2002 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P2002
- Malfunction indicator lamp on
- Usually no change in driveability
- Visible soot at the tailpipe in severe cases
Common causes of P2002
- Most likelyFilter substrate cracked or melted, often after an uncontrolled regeneration
- PossibleFilter removed, emptied or bypassed
- PossibleFaulty differential pressure sensor or leaking sensor hoses on pressure-based systems
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Diesel particulate filterParticulate matter sensorDPF differential pressure sensor
What each part of P2002 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 02 | The exact fault in that area. |
What to do next
- Note P2002 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2002
What does P2002 mean?
P2002 means "Diesel Particulate Filter Efficiency Below Threshold (Bank 1)". P2002 means the particulate filter on bank 1 lets too much soot through, typically because the substrate is cracked, partly melted, emptied or bypassed. It is a generic code, so it means the same on every make.
Is it safe to drive with P2002?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2002 fail an emissions test?
Yes, it can. P2002 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2002 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2002 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.