P24A2: Particulate Filter Regeneration Incomplete Bank 1

What it means

Particulate Filter Regeneration Incomplete Bank 1: the control module has detected this fault condition.

At a glance

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

How it works

The DPF on bank 1 traps soot from that exhaust bank, and regeneration burns the soot away under temperature and pressure monitoring. P24A2 sets when the controller detects that bank 1's regeneration did not complete, leaving soot behind and potentially prompting another regeneration attempt.

Common causes

Most likely first.

1. Regeneration interrupted before completion
2. Frequent short or low-speed trips
3. Exhaust temperature too low to complete regeneration
4. Faulty pressure or temperature sensor affecting regeneration

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. Review freeze-frame data and regeneration history to see whether bank 1 regeneration was interrupted by a short trip, low speed, or a shutdown.
2. Check live bank 1 exhaust temperatures and DPF differential pressure, comparing readings with bank 2 if fitted and with the manufacturer's guidance.
3. Inspect bank 1 pressure-sensor hoses and exhaust temperature sensor wiring for blockage, leaks, heat damage, or loose connectors.
4. Check for exhaust leaks around the bank 1 DPF that could prevent the required temperature or distort pressure readings.
5. Scan for engine or sensor faults that could prevent bank 1 regeneration from starting or completing.
6. Assess bank 1 soot load and perform a service regeneration only if the manufacturer's procedure confirms it is safe.

Common fixes

• Repair bank 1 sensor wiring, connectors, or pressure-sensor hoses.
• Repair an exhaust leak at the bank 1 DPF.
• Replace a bank 1 pressure or temperature sensor that fails testing.
• Correct the engine fault or operating condition interrupting regeneration.
• Complete a service regeneration when the soot load and vehicle condition permit.

Can I keep driving?

Avoid repeated short trips and monitor the DPF warning; continued incomplete regeneration can increase bank 1 soot loading and cause reduced power. If the warning escalates or power falls, limit driving and arrange service.