You can usually drive with the DPF light on for a short period (e.g., 30-60 minutes) at consistent highway speeds (over 40 mph/60 km/h) to trigger automatic regeneration, but if the light stays on after this, you must see a mechanic soon to avoid costly damage, as continuous driving with a solid light indicates a blockage that needs professional attention, like a forced regeneration or cleaning, says Coohom, DPF Fixer, and The AA. Ignoring it can lead to reduced performance, lower fuel efficiency, or engine damage, and will cause an MOT failure in the UK.
If your DPF light turns on, the first thing you should do is attempt to initiate a DPF regeneration cycle. This can be done by driving at a consistent speed of at least 40 mph for approximately 10 minutes. This higher sustained speed increases the exhaust temperature, which can often trigger a DPF regeneration.
The cost of DPF replacement in a vehicle can range from $1,000 to $10,000 or more. This cost may vary depending on the make and model of the vehicle, as well as the location and accessibility of the filter. It is recommended to have the filter replaced by a certified mechanic to ensure proper installation and function.
DPFs are designed to reduce soot emissions by 80 %. They need to empty themselves—this is called regeneration. A town-based, stop-start driving style may hinder this regeneration. A DPF warning light is a sign to take a 10-minute drive at a higher speed so the DPF can regenerate.
Active DPF regeneration
If this is the case the warning light will continue to show the filter is still partially blocked. In which case it should be possible to complete a regeneration cycle and clear the warning light by driving for 10 minutes or so at speeds greater than 40mph.
A very common way to begin cleaning a DPF is to use high-pressure, compressed air. You can achieve this best by using a high-pressure cleaning cabinet, which backflush compressed air into the filter and forces ash to dislodge any blockage.
Whilst you can technically drive with the DPF light on, we would advise against this. You should take your car to a qualified mechanic at the earliest opportunity. When the DPF light is solid, it is especially important to visit a garage promptly.
Top 10 vehicles with DPF issues:
The light should go out once the regen process is complete, as long as you give the DPF enough time to reach a high enough temperature. If it doesn't or the light keeps coming on, a professional mechanic will need to force DPF regeneration and clean or replace the DPF if needed.
It's recommended that vehicle owners maintain and clean their DPF regularly as a new DPF could cost between £1000 - £3000 in some cases which is a much higher cost than simply carrying out scheduled checks.
If your DPF is heavily clogged, replacement is likely the best option. In severe cases, cleaning may not be effective at removing all the soot, and a replacement filter is necessary to ensure proper engine performance and emissions compliance.
For passenger cars, the cost of replacing a DPF can range from AUD 1,500 to AUD 3,000 or more. Larger vehicles like buses and trucks could have significantly higher costs due to the larger size and more complex systems.
Average Lifespan Of A DPF
Under typical conditions, a Diesel Particulate Filter (DPF) is designed to last anywhere between 120,000 and 200,000 kilometres. However, this range is not a guarantee, as the actual lifespan can vary widely based on several factors.
If your car has an automatic gearbox, change gears in manual mode, increasing the number of revolutions. However, there's no need to go as far as the rev limiter, as that won't do any good. Drive in this mode for at least 30 minutes. This will trigger a regeneration cycle and your DPF will be cleaned.
How do you clean an exhaust filter? All you need to do is drive! Diesel trucks have a built-in DPF cleaner that burns off excess soot using the heat from the engine. Known as passive regeneration, this process occurs automatically when you maintain a steady highway speed for at least 45 minutes.
So don't ignore it, hoping the DPF light will simply go away. You need to go for a drive where you can get the car up to temperature and keep the revs up - preferably above 3000rpm - for a good few minutes.
Short trips and low-speed driving can cause DPF failure. The DPF requires high temperatures to burn off the accumulated soot and particulate matter. Short trips and low-speed driving do not allow the engine to reach the required temperature, leading to incomplete regeneration and blockage of the DPF.
DPF Cleaning
If you complete the above DPF Regeneration process and the DPF light remains on, it may be time to get your Diesel Particulate Filter professionally cleaned.
DPF Warning Lights, What you Need to Know
A diesel car will display a DPF warning light when there is a problem with the car's diesel particulate filter. This filter reduces the amount of harmful soot emitted by the car and has been required, by law, to be fitted to all diesel cars since 2009.
The best DPF cleaner in Australia depends on the severity of the blockage, with top brands like Penrite (Enviro+), Bluechem, JLM, Wurth, and Liqui Moly offering solutions, from fuel additives that aid regeneration (Penrite, JLM Regen Plus) to professional-grade spray cleaners for removal without disassembly (Bluechem, Wurth, JLM Cleaner Kit). Penrite Enviro+ and JLM Regen Plus are great for maintenance, while Bluechem's DPF Power Cleaner and JLM's specialized kits offer solutions for heavily clogged filters, often used by workshops.
Maintaining engine performance: A clogged DPF can reduce the performance of your diesel engine. Preventing damage: The filter can become excessively clogged, leading to damage to other parts of the engine.
Generally, it's best to avoid driving your car with the DPF light on for more than a few miles. If you're unsure of how long you can drive your vehicle with the warning light on, it's best to consult your owner's manual or a qualified mechanic.
Typical DPF Replacement Costs at Main Dealer
The cost to replace a DPF filter for your car can range anywhere from £1,000 to £3,500 or more, depending on the factors discussed above. On average: Small passenger cars: £1,000 to £2,000. SUVs and larger vehicles: £1,500 to £3,500.
DPF ADDITIVE LEVEL RESET STEPS: