Short answer

The DPF warning light means the filter is loaded with soot and needs to regenerate, or that the system has a fault. A steady light can often be cleared by a sustained drive at steady speed, as many handbooks advise. If it stays on, flashes, or appears with other warnings or power loss, have the vehicle diagnosed.

On this page

What the DPF light looks like

Most manufacturers use an amber symbol of a box with dots inside, representing the filter and trapped soot. Some vehicles show a text message instead. Your handbook confirms which symbol your vehicle uses and what it recommends.

How to clear a DPF warning light

If the light is steady and there are no other warnings, many manufacturers advise driving at a steady speed for a sustained period so that active regeneration can complete. Follow your handbook’s guidance on speed, gear and duration, and only drive where it is safe and legal to do so. If the light goes out, regeneration has worked.

Clearing the light with a diagnostic tool without regenerating or fixing the fault only hides the problem.

Why the DPF light keeps coming on

If the light returns soon after clearing, something is stopping the filter staying clear: frequent short trips, a faulty sensor or hose, an engine fault producing extra soot, or a filter loaded with ash. See DPF not regenerating and clogged DPF.

DPF light after cleaning

If the light comes on after a DPF clean, the ECU’s soot and ash values may not have been reset, a sensor may have been disturbed, or the original cause of the blockage was not fixed. Go back to whoever did the work.

What to do when the DPF light comes on

  1. Check for other warnings

    Note whether the engine management light is also on, the DPF light is flashing, or power has dropped.

  2. Read the handbook

    Find the manufacturer's advice for this light on your vehicle.

  3. Give it a sustained drive

    If the light is steady and the handbook allows, drive at a steady speed so regeneration can finish.

  4. Get it diagnosed if it stays on

    A workshop can read fault codes and soot load, then regenerate, repair or clean as needed.