What does the DPF warning light mean?

The DPF warning light appears on diesel cars fitted with a Diesel Particulate Filter, and comes on when the filter is getting blocked with soot.

It's usually not an emergency, but it's worth acting on rather than ignoring. A DPF is designed to "regenerate" - burn off the trapped soot - during a sustained faster drive, like a motorway run. Lots of short, low-speed journeys around town are the most common reason the filter never gets hot enough to clear itself.

If the light comes on, a 15 to 20 minute drive at a steady higher speed can sometimes clear it on its own. If the light keeps coming back, get it looked at - a fully blocked DPF can lead to reduced power or, eventually, an expensive replacement.