Diesel Particulate Filter Warning Light ON: Causes and How to Fix

Car owners using diesel engines should always monitor their check engine light for the diesel Particulate Filter Warning Light.

The diesel Particulate Filter (DPF) Warning Light as the name implies, is an indication that the Particulate Filter needs immediate cleaning or replacement to avoid limping mode.

This is a broad issue and I’ll advise most diesel engine users to always watch out for the places they purchase the fuel and also perform regular clean-up before the Filter Warning Light comes on.

Because of continuous combustion, soot will inevitably accumulate in a car’s exhaust over time. The purpose of the particle filter is to remove soot from the exhaust. But with time, the filter may become blocked.

Long-term consequences could result from ignoring the soot accumulation. The Diesel Particulate Filter warning light is one of the first signs you’ll have to contend with.

In this article, you’ll learn how possible reasons why the PDF warning light will turn on and how to resolve it.

Diesel Particulate Filter Warning Light ON – Causes

As discussed earlier, the primary reason why the DPF warning light will turn ON is due to a blocked or damaged Particulate Filter.

The light is just displayed to prompt you into taking rapid action before it leads to Limp mode and you can check out how Limp mode causes a restriction to a car movement in our article here.

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Nevertheless, a faulty temperature or pressure sensor could cause the diesel Particulate Filter Warning Light to turn ON due to the wrong signal being sent to the onboard computer system.

Regardless, the main cause of the DPF warning light displaying is an excessive buildup of soot in a vehicle’s particulate filter.

Diesel Particulate Filter Warning Light ON – Fix

Since the DPF warning light is associated with a clogged Particulate filter, it’s regarded as a major issue that needs immediate attention.

Here are some of the fixes you can implement to clear the diesel Particulate Filter Warning Light.

1. Drive beyond 40 mph to trigger regeneration

Driving above 40 mph is the most popular remedy for DPF warning light displays. If you decide to do this, leave the crowded area of your city and find a long stretch of roadway.

Once you’re on the road, maintain an engine speed of no less than 2500 rpm while driving at a high speed of at least 40 mph for up to 15 – 30 minutes. Active regeneration will naturally start as a result, of raising the temperature.

The clogged particles will in turn exit through the car’s exhaust. The DPF warning light will disappear in no time.

2. Use DPF cleanser

Using a DPF cleanser is an alternative method for clearing a clogged DPF filter.

Make sure to apply the quantity according to the manufacturer’s advice. Start the car after that, and then drive for 15 to 30 minutes.

After 30 minutes of driving, the DPF warning light will automatically turn off as the cleanser percolates the fuel system.

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You can purchase a DPF cleaner on amazon for as cheap as $17 – $60

3. Particulate Filter Cleaning or Replacement

The first thing that should come to mind is to either clean the Particulate filter of all clogged dirt particles that might have accumulated in it.

If the check light is still turned on after cleaning it then you can consider getting a replacement.

It’s advisable to take your car to a mechanic for this procedure if you aren’t grounded in automotive repairs.

4. Temperature or Pressure Sensor Replacement


Can I Drive with DPF Warning Light ON?

It’s not recommended to drive with your car’s DPF light on. Even though the car may not have any trouble driving on the road, the issue may get worse over time. You run the risk of your car’s filter clogging up with enough soot if you entirely disregard the DPF light.

Your car will automatically enter limp-home mode whenever the soot buildup reaches a certain point where the filter is blocked to assist safeguard the engine.

In order to safeguard the engine, the limp-home mode gradually changes how numerous parts of your car should operate. Driving the car in this situation could not be satisfying for you.


An illuminated DPF warning light should be taken seriously especially when it’s at the early stage.

Failure to curb a clogged Particulate filter will result in limp mode which will make the driving experience frustrating.

You can either use a DPF cleanser, drive at a higher speed or initiate the replacement of damaged parts.

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Nevertheless, if you’re having issues implementing any of the above fixes then you should consider getting the help of a mechanic.

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