P243D says that a regeneration of the bank 2 particulate filter took longer than the calibrated limit. CARB expects the OBD system to notice when a filter fails to regenerate properly under conditions in which it was designed to. No manufacturer publishes this bank 2 code; the bank 1 version P2458 shows what such a limit looks like, for example on VW's 2014 Touareg TDI, where an accumulated regeneration timer above 93.35 min counts as a fault. Low exhaust temperature on that bank, a weak oxidation catalyst, an incorrect temperature or pressure signal and many short trips all drag the process out. A long regeneration costs fuel and puts extra heat into the filter. P243C covers regenerations that come too often, P243E those that end with soot left in the filter.
Medium severity. Can I keep driving?If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.
Bank 2 is the side without cylinder 1, so it only exists on V or boxer engines.
Symptoms
- Regeneration seems to run for a very long time (fan, idle speed)
- Higher fuel consumption
- MIL on
Most likely causes
- Exhaust on bank 2 not reaching regeneration temperature (short trips, low load)
- Oxidation catalyst on bank 2 converting too little fuel into heat
- Temperature or pressure sensor giving wrong values
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P243D means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 4: Emissions
- 3D: Specific fault in that system
Frequently asked questions
Can I keep driving with code P243D?
If the light is on steadily, take a highway drive or go to a repair shop soon. If the car is in limp mode or the light is flashing, do not push the engine.
What causes code P243D?
The most common causes are: exhaust on bank 2 not reaching regeneration temperature (short trips, low load); oxidation catalyst on bank 2 converting too little fuel into heat; temperature or pressure sensor giving wrong values.
Related codes
- P2458Diesel Particulate Filter Regeneration Duration
- P243CParticulate Filter Regeneration Frequency (Bank 2)
- P243EParticulate Filter Regeneration Incomplete (Bank 2)
Sources
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.