P243C: Particulate Filter Regeneration Frequency Bank 2

What it means

The DPF on bank 2 needs regeneration more often than calibrated. Possible causes are an oil-burning engine, fuel-injector leak, short-trip operation, or a sensor offset.

At a glance

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

How it works

The control module tracks how often the bank 2 DPF needs to regenerate to burn off trapped soot. This code sets when regeneration is requested more often than the calibrated interval, which can result from frequent short trips, excess soot, oil entering the exhaust, or inaccurate pressure or temperature readings.

Common causes

Most likely first.

1. Frequent short trips or low-speed driving interrupting regeneration
2. Excessive soot from a fuel-injector or combustion fault
3. Engine oil entering the exhaust
4. DPF pressure or temperature sensor giving inaccurate readings

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 frequency and history, soot estimate, and DPF pressure readings.
2. Check whether recent driving has mostly involved short trips or low speeds that interrupt the bank 2 regeneration cycle.
3. Inspect bank 2 DPF pressure-sensor hoses and exhaust temperature sensor wiring for leaks, damage, loose connections, or implausible readings.
4. Look for signs of excess soot from injector or combustion faults and check for engine oil entering the exhaust.
5. Compare bank 2 sensor readings and regeneration data with the manufacturer's specification, and address any underlying engine or sensor fault before requesting regeneration.

Common fixes

• Repair a leaking, blocked, or damaged bank 2 DPF pressure-sensor hose.
• Repair sensor wiring or replace a bank 2 pressure or temperature sensor confirmed inaccurate.
• Correct injector, combustion, or oil-consumption problems that are adding soot or ash.
• After fixing the cause, allow or carry out regeneration only as directed by the vehicle's service procedure.

Can I keep driving?

If power is normal and no DPF warning is demanding immediate attention, limit repeated short trips and arrange diagnosis soon. Frequent regeneration raises fuel use and can lead to power loss or greater DPF restriction if the underlying cause continues.