P243D: Particulate Filter Regeneration Duration Bank 2

What it means

Regenerations on bank 2 take longer than calibrated to complete - typically a low EGT during the cycle (cold weather, short trips) or a partially aged catalyst before the DPF.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test

How it works

During regeneration, the bank 2 DPF heats up so trapped soot can burn away; the control module uses exhaust temperature and pressure data to track the cycle. This code sets when bank 2 regeneration takes longer than expected, often because the exhaust does not reach or maintain suitable temperature or the readings are inaccurate.

Common causes

Most likely first.

1. Frequent short trips or low-load driving preventing regeneration temperatures
2. Exhaust leak reducing temperature or affecting sensor readings
3. Faulty exhaust temperature sensor or wiring
4. Restricted DPF or deteriorated oxidation catalyst

Symptoms

• Check engine light or DPF warning light on
• Power loss / limp mode
• Increased fuel consumption
• Failed forced regeneration attempts

How to diagnose it

1. Use a scan tool to review freeze-frame data, bank 2 regeneration duration and history, exhaust temperature readings, and DPF pressure.
2. Check whether short trips, cold weather, or sustained low-load driving have kept the bank 2 exhaust too cool during regeneration.
3. Inspect the bank 2 exhaust for leaks near temperature sensors and the oxidation catalyst, since leaks can affect heat and sensor readings.
4. Check bank 2 exhaust temperature sensor connectors and wiring for damage, then compare cold and warmed-up readings for plausibility.
5. If sensor readings are credible, compare DPF pressure and catalyst performance with the manufacturer's specification to identify a restricted filter or deteriorated oxidation catalyst.

Common fixes

• Repair an exhaust leak affecting bank 2 temperature or pressure readings.
• Repair damaged exhaust temperature sensor wiring or replace a confirmed faulty sensor.
• Correct driving or engine conditions that prevent bank 2 exhaust from reaching regeneration temperature.
• Clean or replace a restricted bank 2 DPF or service a deteriorated oxidation catalyst when testing confirms the fault.

Can I keep driving?

Avoid repeatedly interrupting a regeneration and arrange diagnosis if the warning persists or power falls. A bank 2 filter that cannot complete regeneration may accumulate more soot, increase fuel consumption, and eventually restrict exhaust flow.