can you do a regen with check engine light, DPF regen symbol on car dashboard

Can You Do a Regen with Check Engine Light

Diesel particulate filter (DPF) regeneration is an essential task to maintain the engine’s optimal performance. However, what happens when the check engine light illuminates? Can you do a regen with check engine light?

Yes, you can do a regen with the check engine light. But there is a factor you should consider before doing a regen with the check engine light. 

When I was in your situation, I did deep research to find the answer to the question, “Can you do a regen with check engine light?”

In this article, I will explain the answer to the topic and tell how I regenerated diesel particulate in my truck as a step-by-step guide.

What is DPF Regen?

DPF regen means diesel particulate filter regeneration. It is the process of removing particulate matter from the filter. Soot and unburned fuel are the particulate matter in the exhaust system. They are captured by the diesel particulate filter.

What Is the Need for Cleaning Diesel Particulate Filter?

As the DPF captures particulate matter, over time it becomes clogged with those particles. This leads to an increase in backpressure and also reduces the performance of the engine. So, DPF regen is crucial for the vehicle.

What Are the Methods of DPF Regen?

Mainly, there are 3 methods of DPF regeneration.

Regeneration MethodDetails
Passive RegenerationContinuous regeneration occurs during normal driving conditions. Exhaust temperature helps burn off trapped soot.
Active RegenerationInitiated by the engine control unit (ECU) when the DPF reaches a certain threshold. Additional fuel is injected into the exhaust system to generate heat and burn off trapped particulates.
Forced RegenerationRequired when passive and active regeneration methods are insufficient.

How Can I Know If My DPF Needs a Regen?

Here are the main symptoms you can experience when your DPF is blocked: These signs will increase and get worse when blockages increase.

  1. DPF indicator lights come on the dashboard.
  2. Engine is low on power and cannot rev to high speeds.
  3. Black fume from the exhaust at high RPMs.
  4. Odour of diesel while driving.
  5. Low fuel economy.

If you are experiencing one or more of the signs I mentioned above, it is best to regen DPF. But the problem is, can you do a regen with check engine light? Keep scrolling. The answer will come to your mind even before I mention it.

Why Does the Check Engine Light Come On?

The check engine light mainly comes on if there is a problem with the engine or transmission. Sometimes the check engine light is triggered indirectly due to a malfunctioning AC compressor or a problem in the exhaust system. For the regen process, it is better to have a fully functioning exhaust system.

Malfunctioning catalytic converters and failing oxygen sensors are the exhaust system problems for the check engine light.

What are the Jobs of the Catalytic Converter and the Oxygen Sensor?

The catalytic converter decreases the levels of harmful gases in the exhaust. It converts these bad gases into less harmful gases and water vapor through a series of chemical reactions.

The O2 sensor measures the amount of unburned oxygen in the exhaust. It works in conjunction with the electronic control unit (ECU) of your car to determine the ideal air-to-fuel ratio for optimal engine performance.

Do you think these two affect the DPF regeneration process? No, they will not. But if the catalytic converter is the cause of the check engine light, some harmful gases will be released into the atmosphere. That is the thing I mentioned in the beginning as the factor you need to consider.

Can You Do a Regen with Check Engine Light?

Let’s move on to our question. Can you do a regen with check engine light? Yes, you can. So how can you do a regen with check engine light?

The check engine light was on in my Hilux. In my research, I found there is no problem with regenerating the diesel particulate filter with check engine light. So here is how I regenerated my DPF:

I found a safe and clear area to park my Hilux.

First, I parked my Hilux in the corner of the garden.

Then I put the truck in neutral and set the handbrake. If your vehicle has an automatic gearbox, put the gear into the ‘P’ position.

Next, I pressed the accelerator to 3000 RPM until the engine temperature reached the middle level of the dial.

I pressed the DPF switch to start the regeneration process. The DPF switch was located on the right side of the steering wheel. Then the DPF process was started, and It was indicated on the dashboard.

Tip: If the DPF process doesn’t start on your vehicle, it is because of the low temperature of the engine. So, make sure to heat the engine.

Once the process was completed, my dashboard indicated that the DPF was clean.

Finally, I revved the engine a few times to clear the exhaust hose.

Note: White smoke will be emitted in the DPF regeneration process, and the smell of the smoke will change. It is normal and not a cause for concern.


Can you do a regen while driving?

Yes, you can do a regen while driving. It usually takes between 10 and 30 minutes for a regeneration cycle to finish.

Does the DPF filter regenerate automatically?

Yes. It is called active regeneration. When the filter reaches its limit of about 45%, extra fuel is injected into the filter. The additional fuel increases the temperature of the exhaust and burns the soot that has been accumulated. But the travel must be long enough to finish an entire cycle.

What is the recommended RPM for DPF regeneration?

The general rule of thumb is to keep the engine running at a speed and rpm of at least 2500 and at least 40 mph, respectively. For more detailed instructions, see the owner’s manual for your car.

Can I clear DPF by revving?

Yes, you can clear DPF by driving the car over a long distance while maintaining high revs per minute. By doing this, the soot obstructing the DPF filter is burned, and the exhaust heat is increased. It is ideal to travel on a highway where you can maintain a constant speed for the vehicle.


Again, can you do a regen with check engine light? Yes, you can do it, and it is normal and safe. Have a nice ride!

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