Mercedes Diesel Particulate Filter (DPF) Problems | Cleaning | Regeneration
Are you having problems with your Mercedes Diesel Particulate Filter (DPF)? Maybe your local mechanic or Mercedes dealer is quoting you $4000+ for a DPF replacement. In this article, you will learn more about DPF and possible fixes without replacing it. Take a few minutes to read this article before spending several thousand dollars on a new DPF filter.
Symptoms
This is a list of symptoms you may notice when there are issues with the DPF.
- Check Engine Light On
- The vehicle goes into limp mode
- Reduced speeds.
- Poor acceleration
- No throttle response
- A decrease in fuel efficiency
Problem
Your Mercedes check engine light comes with one or more codes related to the DPF filter soot content being too high. These fault codes affect many 2010 and newer Mercedes models, including E S GL ML R G Bluetec versions.
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On Sprinter vans, throttle response is poor, and there is hardly any acceleration, no matter how hard you press the gas pedal. Vehicle speed may be limited to 40 mph. An owner will get generic fault codes scanned with a generic OBD2 scanner. If a professional diagnostic scanner is used, such as the YOUCANIC Full System Scanner, you will get the following error:
- 11A700 Diesel particulate filter – The soot content of the particulate filter is too high for regeneration.
- 11AF00 Diesel particulate filter – The soot content of the particulate filter is too high for regeneration.
- P244B Diesel particulate filter (DPF) – differential pressure too high
- P2458 Diesel Particulate Filter Regeneration Duration
- P2463 Diesel Particulate Filter Restriction – Soot Accumulation
Other Possible Codes.
- P1471Diesel particulate filter (bank 1) regeneration not completed
- P2002 Diesel particulate filter (bank 1) efficiency below threshold
- P2003 Diesel particulate filter (bank 1) particulate mass too high
- P242F Diesel particulate filter (bank 1) regeneration not active
- P244A Particulate filter differential pressure too low
- P224B Particulate filter differential pressure too high
- P2452 Particulate filter differential pressure sensor malfunction
- P2453 Diesel particulate filter differential pressure – sensor malfunction
- P2454 Diesel particulate filter differential pressure – sensor voltage too low
- P2455 Diesel particulate filter differential pressure – sensor malfunction
- P2458 Particulate filter regeneration maximum regeneration time exceeded
- P2459 Particulate filter regeneration, regeneration frequency implausible
Just because you are getting an error code “Mercedes Diesel Particulate Filter The soot content of the particulate filter is too high for regeneration,” it does not mean that the DPF needs to be replaced.
If you have this problem, don’t rush into replacing the DPF filter. A DPF fault code doesn’t always mean you need to replace the Diesel Particulate Filter (DPF), a repair that can run from $4000 to $6000. This problem is often fixed by manually forcing a DPF regeneration.
Ask your Mercedes-Benz dealer or mechanic to perform a forced DPF regeneration manually. If you have a professional scanner, you could carry DPF regeneration. Make sure to follow your scanner’s instructions before it starts DPF regeneration.
What is DPF Regeneration
During the regeneration process, the soot built inside the DPF is removed. This is done by allowing the DPF (catalytic converter) to reach temperatures up to 600 C. This allows the soot to burn and be pushed out with the exhaust gasses. This process is done passively or can be a forced regeneration.
Passive Regeneration
Your Mercedes will automatically start the regeneration process while driving without you knowing. Unless the check engine light is on for another reason or specific criteria are not met, it can cause the regeneration process never to be completed. If the regeneration process does not start independently, you will eventually get so much soot built up that one or more of the above codes will be triggered.
Forced DPF Regeneration
You can force Mercedes DPF regeneration with a professional diagnostic scanner like Mercedes Star Diagnostic on eBay. Regeneration can be carried out with the vehicle driving or parked. The driving method is preferred and less risky.
Certain conditions must be met during this process, and the engine RPMs will be kept at 2000 for approximately 30 min. The scanner must initiate the procedure.
Several conditions need to be met, some of which include:
- Engine coolant needs to reach the average operating temperature.
- The catalytic converter needs to be over 200C as a starting point.
- Turn on the lights and rear defroster.
- Set the climate control to blow at max speed
- The Hood needs to be closed.
These are only a few of the conditions as they vary between models. The scanner will display all the steps you must follow for manual DPF regeneration.
On most scanners, DPF regeneration can be started by going to:
- Maintenance >
- DPF >
- CDI Module >
- Activation / Tests / Adaptations >
- Manual DPF regeneration
Manual Mercedes DPF regeneration takes from 30 to 50 min. During this time, the DPF temperature reaches up to 600C.
Once the process has been completed, the codes above will change from Current to Stored status. This will allow you to clear the codes you couldn’t get before DPF regeneration. Once you clear the codes, your Mercedes E R ML GL S Sprinter 320 350 2500 3500 should be out of limp mode and drive without restrictions.
Why wasn’t passive regeneration not completed?
Because the diesel soot particles in the DPF are not being burnt off at high temperatures, the vehicle is typically not doing enough highway miles or driving too frequently in the city. Another possibility is that the check engine light is on for another problem, automatically passive DPF regeneration.
DPF Cleaning
If the DPF is excessively blocked with soot and ash, a professional cleaning or a replacement DPF will be required. A DPF can be cleaned by removing the upstream DPF sensor and spraying fluid to clean the build-up inside the DPF. This is an alternative solution to replacing the DPF.
The following video shows you how to clean a DPF filter. A popular product is LIQUI MOLY Diesel Particulate Filter Cleaner.
Frequently Asked Questions
What is the purpose of the diesel particulate filter?
To reduce particulate emissions.
What can prevent passive DPF regeneration?
Any fault in the ECU that has triggered the check engine light will prevent regeneration from automatically happening—short trips.
When do I need to replace the DPF?
If the DPF is excessively blocked with soot and ash, then a professional cleaning or a replacement unit will be required.
Are DPF filters and catalytic converters the same?
Catalytic converters and Diesel Particulate Filters (DPF) are not the same; they serve different purposes in a vehicle’s exhaust system, though both aim to reduce pollutants.
Catalytic Converter:
Found in both gasoline and diesel engines.
Its primary purpose is to reduce harmful emissions of hydrocarbons, carbon monoxide, and nitrogen oxides by converting them into less harmful substances such as water vapor and carbon dioxide through chemical reactions.
It usually contains a honeycomb structure coated with precious metals like platinum, palladium, and rhodium, which act as catalysts for these chemical reactions.
Diesel Particulate Filter (DPF):
Found only in diesel engines.
Its main function is to capture and store exhaust soot (particulate matter) to reduce diesel particulate emissions.
The collected soot is periodically burned off at high temperatures to regenerate the DPF.
It typically contains a wall-flow filter that traps the soot.
In modern diesel vehicles, you will often find a catalytic converter and a DPF as part of the exhaust system to meet stringent emission standards. The catalytic converter handles the chemical pollutants, while the DPF tackles the particulate matter common in diesel exhaust.
How often do I need to carry DPF regeneration?
It can be as early as 60,000 miles or even up to 300,000. There is no set limit because your vehicle should carry out passive DPF regeneration at random times as you drive. The only time that forced DPF regeneration is required is when the possible DPF regeneration could not be started automatically.
We hope you find the Mercedes Diesel Particulate Filter (DPF) Problems | Cleaning | Regeneration guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.
