The exhaust particulate filter warning light is a light that will show up on the dashboard of a diesel car when soot from the exhaust has reached high levels. Diesel engine exhausts are fitted with a particulate filter that is designed to control high emission levels. It catches the larger particles of soot coming from the exhaust. Here is everything you need to know if you see your exhaust particulate filter warning light turn on.

Why is My Exhaust Particulate Filter Warning Light On?

The exhaust filter on your diesel car will clog up over time, which can lead to restricted airflow and cause your car’s performance to deteriorate. Car manufacturers have come up with several ways to regenerate the filter to prevent this. Regeneration occurs when the exhaust temperature is raised high enough to burn away the soot particles, turning them to ash. The exhaust particulate warning light will usually show when the filter needs to be regenerated.

What is the Exhaust Particulate Filter Warning Light?

When you are driving your car, its computer is always monitoring the levels of soot within the filter to determine when the regeneration process is needed. However, the car needs to reach high speeds for the exhaust to be hot enough to burn the soot. If you don’t travel on the motorway very often, the exhaust may never get hot enough, and your warning light will show. If you see the warning light on your dashboard, you will usually be able to fix the problem by taking your car to a higher-speed road such as a motorway and driving at a higher speed – at least 40MPH for ten to fifteen minutes.

What Does it Mean When the Exhaust Particulate Filter Warning Light is Flashing?

A flashing light may occur when the exhaust filter needs to be regenerated. This will usually depend on the model of the car. If you see the light flashing, you will need to take your car to a higher-speed road where you should drive it for ten to fifteen minutes at a higher speed to burn the soot away from the filter.

How Does the Exhaust Particulate Filter Warning Light Work?