P2003 is set when the particulate filter of bank 2 lets too much soot slip through, which almost always points to a cracked, partly melted, hollowed-out or bypassed core. Separate filters per bank are uncommon, so the code is rare. No manufacturer documents P2003 publicly; GM and Ford explain the detection under the bank 1 code P2002: older systems judge the flow resistance of a freshly regenerated filter, newer ones use a resistive PM sensor behind it, which signals too early when soot gets past the filter. CARB requires the system to catch a filter whose leakage pushes PM beyond the limit and also one whose substrate is missing. A forced regeneration will not cure a broken filter; it has to be replaced. The warning lamp may be the only sign, with soot at the tailpipe if the leak is large.
Medium severity. Can I keep driving?You can drive in moderation to a repair shop, although this side of the exhaust expels more particulates and the car may fail an emissions inspection. Get it checked soon so you are not driving with an unreliable soot load reading.
Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.
Symptoms
- Malfunction indicator lamp on
- Visible soot at the tailpipe with a large leak
- Engine performance normally unaffected
Most likely causes
- Bank 2 filter core cracked or melted after an overheated regeneration
- Filter on bank 2 removed, emptied or bypassed
- PM sensor or differential pressure measurement on bank 2 giving false values
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It affects emissions.
What each character of P2003 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 0: Subsystem depends on the code range
- 03: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2003?
You can drive in moderation to a repair shop, although this side of the exhaust expels more particulates and the car may fail an emissions inspection. Get it checked soon so you are not driving with an unreliable soot load reading.
What causes code P2003?
The most common causes are: bank 2 filter core cracked or melted after an overheated regeneration; filter on bank 2 removed, emptied or bypassed; pM sensor or differential pressure measurement on bank 2 giving false values.
Related codes
- P2002Diesel Particulate Filter Efficiency Below Threshold (Bank 1)
- P2465Diesel Particulate Filter Differential Pressure Too High (Bank 2)
- P24AFParticulate Matter Sensor Circuit Range/Performance
Sources
- law.cornell.edu: 13 CCR 1968.2
- gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
- en.wikipedia.org: Diesel particulate filter
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.