DPF regeneration: your questions answered

DPF regeneration Hilux

Although Toyota’s passenger car range is predominantly focused around petrol-electric hybrid powertrains, the Land Cruiser, Hilux and Proace models are fitted with diesel engines. A diesel particulate filter (DPF) is a feature of these models, and you may have heard about the need for regular DPF regeneration. What does this component do and how do you take care of it?

What does a diesel particulate filter (DPF) do?

The DPF is fitted within the exhaust system and is designed to catch soot particles and nitrous oxide (NOx) from the combustion process that would otherwise be released into the atmosphere. The DPF is highly effective and traps around 80% of these harmful particulates.

DPF regeneration

Why do modern diesel engines need a DPF?

European legislation places strict exhaust emissions targets on all vehicle manufacturers. From September 2009, the Euro 5 legislative standard came into effect, part of which required all diesel cars registered from that point on to be equipped with a diesel particulate filter, or DPF.

These filters are used throughout the industry in all diesel-powered passenger vehicles, and their efficiency is vital now that stringent Euro 6d emissions standards are in force.

Do I need to replace a DPF during normal servicing?

Diesel particulate filters do have a capacity limit and can become full. But unlike traditional air, oil or pollen filters that need to be exchanged manually at regular intervals, the DPF has a much longer service life and is designed to regenerate to restore its performance.

The car’s electronic control unit (ECU) is programmed to do this automatically, neutralising the soot by burning it off at high temperature within the exhaust system while the vehicle is running. All modern cars with diesel engines follow this procedure.

DPF regeneration Proace

How does DPF regeneration occur?

The regeneration occurs automatically, usually without the driver being aware that it is taking place. In the majority of cases, the process is carried out when the engine and exhaust system has reached normal operating temperature and the vehicle is travelling at over 40mph.

However, if your driving is limited to urban areas, the low speeds and frequent stops mean the conditions for normal regeneration do not exist. In these instances, the ECU monitors the accumulation of soot and instructs an alternative regeneration programme to begin well before the filter becomes saturated.

This programme injects small quantities of fuel into the engine after combustion, which increases the temperature within the exhaust system and creates an environment where it is possible to safely burn off the soot.

This method is very successful within the small percentage of vehicles where normal regeneration is not possible. However, due to the nature of city traffic, the regeneration process can be interrupted when the vehicle completes its short journey and is turned off. If this occurs, the ECU is programmed to recommence the process when the engine is restarted and back up to temperature again.

DPF regeneration Land Cruiser

How can I help prevent DPF blockages in my Toyota?

Follow these four simple actions:

1. Regularly drive your Toyota on highways at speeds of between 40-55mph for around 20-30 minutes.

2. Avoid spending unnecessary amounts of time with the engine idling.

3, Try to limit the frequency of short journeys where the engine is running for less than ten minutes.

4. Do not ignore dashboard alerts related to the DPF.

Will I be warned if all DPF regeneration processes have been unsuccessful?

Very occasionally, use of the vehicle might be such that it will have been impossible for the ECU to complete the administration of any regeneration procedure. At this point, the DPF will have become overloaded and stopped functioning, so your Toyota will illuminate a warning light in the dashboard. It will then be necessary for the soot to be neutralised and the filter regenerated manually at a main dealer.

It is extremely unwise to ignore this visual warning as the DPF can become irreparably damaged. What’s more, it is illegal to remove the filter entirely.

Learn more: What is the exhaust gas recirculation valve and what does it do?

591 comments

  1. Hi, my hilux (SL21OBO) regens very regularly, every 150-250 miles. Most of my journeys are fast road journeys and I very rarely go into towns or cities. I also have to refill the adblue every 1800-3000 miles. Is this normal?

    1. Hi Craig,
      The mileage between regenerations is about right in order to meet emission levels.
      How the vehicle is loaded/used will affect the AdBlue consumption rate.
      Your Toyota Centre will be able to physically inspect your vehicle if you have any concerns.
      Thanks.

  2. I have a 2021 UK hylux 2.8 auto
    I noticed on a journey on the motorway total mileage 440 miles my hylux dpf regenerated
    Five times is this normal ? Please advise

    1. Hi there,
      Thanks for your comment.
      In the majority of cases, the regenerations process is carried out when the engine and exhaust system has reached normal operating temperature and the vehicle is travelling at over 40mph. So if you are on the motorway, this may happen more frequently.
      There are also other factors that can affect the regeneration frequency such as how the vehicle is loaded.
      Your Toyota Centre will be able to physically inspect your vehicle if you have any concerns.
      Thanks.

      1. Thank you for getting back Iam getting confused I thought the regeneration
        Was between 150 -300 miles

      2. Hi there,
        As mentioned there are many factors that can affect the regeneration frequency.
        Regeneration is important to ensure that your vehicle is compliant with emissions standards.
        However, your Toyota Centre would be able to check your vehicle for you if you wish.
        We hope this helps.
        Thanks.

    1. Hi there,
      There isn’t a specific list which we have available.
      However, this can include factors such as driving style and how the vehicle is loaded.
      Thanks.

  3. Hi Good afternoon I have recently had trouble with my 2016 Toyota Auris Hybrid. On one of my remote keys the central locking would not open or lock yet the ignition sequence worked ok. On my other key central locking worked and ignition sequence worked. The problem was eventually solved at my local dealer as being a faulty key which according to them could not be re-programmed.
    My question is that always having had my Auris serviced at this dealer and consequently qualifying for “TOYOTA RELAX” why did the dealer say that my key was not covered on the “RELAX” warranty, and that cost for a replacement would be £316.00 + programming costs
    The “RELAX” BROCHURE I hold states among its bullet points “full parts and labour cover”.

    1. Hi there,
      Thanks for your comment.
      Referring to the terms and conditions, except the remote controls in your keys, they are not covered by Toyota Relax.
      Thanks.

  4. My new Hilux Invincible X auto (registered March 2022) is only delivering 12mpg when towing, and has used all of its adblue in 1800 miles. Surely this can’t be right? It cost me £500 in fuel and adblue to drive 700 miles over the last 2 days!!!

    1. Hi Dan,
      Thanks for your comment.
      Fuel economy can vary whilst towing different loads.
      Can we confirm how much you were towing at this time please?
      Thanks.

      1. A 2.7 tonne mini digger on a trailer (total weight 3.2 tonnes (ish)). Only me in the truck, no tools etc. 60mph motorway driving, same figures with and without cruise control.

      2. Hi Dan,
        With a fault free vehicle, potential factors affecting fuel and AdBlue consumption are vehicle load and potential driving style.
        It is difficult to know the finer details remotely unfortunately.
        Your Toyota Centre would be best placed to inspect this if you would like.
        We hope this helps.
        Thanks.

    2. For comparison, I tow a 1700kg caravan with the Hilux Invincible X, 2.8 litre diesel automatic, 2021. It has about 80kg in the truck bed and 100kg nose weight on the towball. Typically over 200 miles, half motorway, half two lane roads, regeneration occurred twice, adblue was hardly used and my mpg was 22.3.

  5. Hi,
    I have a 2017 Hilux, it regens 2-3 times per day whilst doing approximately 100 miles per day unladen. Today I had people beeping me on the motorway because there was so much smoke coming out, this doesn’t seem right. Please advise!
    Thanks

    1. Hi Harry,
      Thanks for your comment.
      We would recommend taking your Hilux to your nearest Toyota Centre for further inspection.
      Thanks.

      1. Is this connected to the issues experienced in Australia where Toyota has just lost a Class Action arising from customer problems with the DPF. If so, will Toyota be conducting a recall in the UK.

      2. Hi David,
        This is not something we have any information on at this time.
        Thanks.

  6. CHR Icon 21 plate. My road sign assist system is totally unreliable. It spends 80% of the time in red e.g. shows red at 45mph in a 50mph speed limit; shows red at 34 mph in a 40mph speed limit; it scans motorway gantry that show 60mph as 80mph in red; I have video & photos showing all the constant issues. I think you get the idea. Totally appalled by the lack of customer care from toyota. None of the issues listed in the user manual are relevant and your disclaimer stating it has service limitations. So I presume the limitation is it being incorre t 80% of the time! It’s not road specific. It’s not weather dependent. It’s not dependent on using apple car play; it’s not dependent on scanning the back of a truck; it’s not dependent on location its just all the time. Your answer was limitations to the system. Totally disgusting. And yes I know how it should work as we had CHR dynamic for 3 years! Toyota your quality control & customer care has gone down the pan!

    1. Hi Claire, we’re sorry to hear this.

      If you believe that there is an issue with the system in your C-HR, please get in touch with your local Toyota Centre to allow them to investigate this in person.

      Thanks,

      Toyota UK

      1. Thanks for your reply. I have. It has been back 4 times. There is an issue with it but all Toyota did was send the service team a copy of the page 404 3-5. Which lists a whole host of reasons as to why it may not work (none of which are applicable) then you guys also said it has limitations! Limitations for it reading correctly. Now what? I am totally unhappy. There is a case reference for it as well.

      2. So what do you suggest now? My concerns and the issues have been raised on numerous occasions. It has been witnessed by the service manager and a case raised withToyota. Our local Toyota dealership are aware as I said earlier. I am shocked that you spend money on a car it does not work correctly but I’m expected just to accept that? Not good customer ethics. Would you be happy if it was your car?

      3. Hi Claire,
        Please provide case reference number so we can pass these comments onto our Customer Relations team.
        Alternatively, we can open a new case on your behalf.
        Thanks.

    1. Hi Claire,
      Thank you for providing your case number.
      We have passed on your comments to our Customer Relations team who will be able to best advise on actions going forward.
      Thanks.

      1. I look forward to their response seeing as it has not been good so far 🤦‍♀️

      2. Hi Claire,

        Sorry, it looks like our previous comment didn’t publish. We recommended that you take your vehicle back to your centre. So far, it appears that no fault has been found with your vehicle on your previous visits.

        We understand that this will disappoint you, so we recommend contacting customer relations directly on 0344 701 6202.

        Apologies. Thanks.

  7. Well the plot thickens! Obviously the issue is still not fixed. I spent 45 mins on the phone today. Got through to customer relations. I asked to speak to someone about the road sign assist. I was then put through to the road SIDE assist!! Then asked to be put back to customer relations waited on hold and continued on hold. Then got a message saying the office was now closed that was at 1545hrs! I will have to call back again tomorrow at 0930hrs. Totally rubbish!

    1. Hi Claire,
      We are sorry to hear about this and we completely understand your frustration.
      We will pass on your feedback to our Customer Relations team.
      Please let us know if there is anything else we can do to assist you.
      Thanks.

      1. I have spoken with the customer relations team and I am now going to the motor ombudsman.

  8. Hi got a 2019 hilux with dpf full on the dash, engine management and traction control lights also light up on dash tried driving for an hour in 3rd gear and also a regeneration button but when it is pressed nothing happens?

    1. Hi Greig,
      Thanks for your comment.
      Please contact your nearest Toyota Centre, they will be able to physically inspect your vehicle and provide any necessary repairs.
      Thanks.

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