How do I manually start DPF regeneration?

Yes — many modern diesel vehicles let you initiate a forced DPF regeneration via the car’s service menu or a compatible diagnostic tool. If your model doesn’t support manual regeneration, the system will usually attempt it automatically when you drive at highway speeds.

Diesel particulate filters (DPFs) trap soot from the exhaust. Over time, the filter fills and must be burned off in a regeneration cycle. While some cars manage this automatically during normal driving, others require a manual intervention if you do short trips or if a regeneration fails. This guide explains how to trigger manual regeneration safely, what you’ll need, and what to expect.

Understanding when you might need to intervene manually

Automatic DPF regeneration relies on heat from the exhaust to burn off soot. If you predominantly take short trips, frequent idling, or your vehicle has a high soot load, you may see a warning light or a regeneration fail. In these cases, manual regeneration can help restore normal operation. Not all vehicles support manual regen; always check your owner’s manual or consult a dealer or technician before attempting.

Manual regeneration via the vehicle’s built-in options

Use this path if your vehicle supports a forced regeneration from the dashboard or service menu. Not all models have this feature; check your owner’s manual or speak with a dealer.

Prerequisites

• Park in a safe, well-ventilated area with the engine at normal operating temperature and the parking brake engaged.


• Ensure you have sufficient fuel; a regen can require extra fuel to maintain the correct exhaust oxygen balance.


• Be aware this process can raise exhaust temperatures and may feel like the engine works harder during regeneration.

If your car supports it, follow the steps below to start a forced regeneration from the vehicle’s service or maintenance menu. Exact wording and locations vary by make and model.

• Navigate to the vehicle’s maintenance or service menu on the instrument cluster or infotainment system. Look for options labeled “DPF Regeneration,” “Forced Regeneration,” or similar.


• Select Start/Yes to initiate regeneration. Confirm any warnings about high exhaust temperatures and potential fuel use.


• Let the regeneration run until the vehicle indicates completion. This can take roughly 10–30 minutes depending on soot load and system design.


• After completion, perform a drive cycle as recommended by your vehicle to cool and stabilize the system and to finalize the regeneration.

If the built-in regeneration completes successfully, the dashboard indications should clear. If it fails or the DPF light remains on, consult a technician or dealership for a diagnostic check.

Manual regeneration via diagnostic tools or workshop software

If your vehicle does not offer a built-in forced-regeneration option, or you want a more controlled approach, a diagnostic tool can be used to trigger regeneration. This requires the correct equipment and software and should be done by someone comfortable with vehicle diagnostics. Always ensure the vehicle is supported by the tool and follow the tool’s prompts.

Required gear

• A Windows-compatible OBD-II scan tool or manufacturer-specific diagnostic tool, plus the appropriate software.


• Access to a safe, well-ventilated workspace and a vehicle that is in good mechanical condition.


• Basic understanding of how to connect the tool and interpret live data (soot level, fuel quality, exhaust temperature).

Proceed with caution, following the tool’s instructions exactly to avoid unintended engine or exhaust damage.

• Connect the tool to the OBD-II port (usually located under the dashboard) and turn the ignition to ON. Leave the engine off unless the tool requires it.


• Open the software, select your vehicle, and navigate to the DPF/Exhaust or Regeneration function.


• Choose “Regenerate” or “Forced Regeneration” and follow prompts. The tool will initiate the procedure and display live data (soot load, exhaust temperature, etc.).


• Monitor the process and wait for a completion message. Then perform a drive cycle as advised by the tool or manufacturer to finalize the regen and clear codes.

When successful, the DPF should show reduced soot load and the warning light should go out. If the regeneration cannot be completed, or fault codes persist, seek professional service to inspect the DPF system and related sensors.

What to expect during a regeneration

During a regeneration, the engine management system increases exhaust temperatures and may adjust fuel trims to maintain the necessary heat. You might notice a brief change in engine feel or sound, and the exhaust system will be hotter to the touch. Registrations can last anywhere from 10 to 40 minutes depending on soot load and driving conditions. If you experience an abnormal shutdown, warning lights remaining on, or unusual sounds, stop and seek professional help.

Safety, etiquette, and best practices

To protect the DPF and your safety, keep the following in mind:

• Only initiate manual regeneration in a safe, well-ventilated area away from flames or fuel spills.


• Avoid interrupting the regeneration once started; turning off the engine mid-process can cause additional fault codes or damage.


• After a forced regen, complete a recommended drive cycle to allow the system to cool and reset.


• Regular maintenance and mindful driving (regular highway trips when possible) help keep DPF soot levels manageable and reduce the frequency of forced regenerations.

If your DPF warning light returns after a regen or you see repeated regeneration failures, consult a qualified technician. Repeated/regeneration problems can indicate other issues such as faulty sensors, injector problems, or a need for DPF cleaning or replacement.

Summary

Manually starting a DPF regeneration is possible on many modern diesels, either through a vehicle’s built-in service menu or via a diagnostic tool. Not all models support manual regeneration, and some drivers may only be able to complete regeneration by driving on highways. Always consult your owner’s manual or a qualified technician before attempting, and follow safety guidelines to avoid exhaust hazards. With proper maintenance and mindful driving, you can keep your DPF operating efficiently and minimize regeneration-related disruptions.

Final takeaway

Manual regeneration can be a useful tool for maintaining DPF health, but it depends on your vehicle’s capabilities and software. When in doubt, seek professional advice to ensure you don’t damage the exhaust system or compromise performance.

How to do a parked DPF regeneration?

And apply the parking brake making sure not to touch the foot. Pedals. Finally press and hold the parked regen switch for 2 seconds then release.

Can I manually force DPF regeneration?

There are two main types of DPF regeneration: passive and active, however, DPF regeneration can be performed manually using a scan tool.

How long does it take to force DPF regeneration?

A forced Diesel Particulate Filter (DPF) regeneration typically takes 20 to 60 minutes, although it can sometimes take longer, up to 90 minutes, with some heavy-duty engines sometimes taking up to 1.5 hours. If the process takes significantly longer than an hour or 90 minutes, it could indicate a problem with the system, such as a clogged filter or faulty sensor, that needs professional diagnosis. 
Factors affecting the duration

• Soot level: A more heavily clogged filter will take longer to regenerate. 
• Engine conditions: Engine temperature and other factors can affect how long the process takes. 
• System issues: Clogged components, like the doser injector tip, or sensor failures can extend the time. 
• Engine model: Different engines have different parameters; for example, some heavy-duty engines may take longer than others. 

What to watch for

• Normal signs: A successful regeneration is often indicated by a distinct smell, a noticeable increase in exhaust temperature, and the engine's idle returning to normal. 
• Signs of a problem: A regeneration that takes much longer than the typical time frame (e.g., over an hour or two) can be a sign of an underlying issue. 

How do you manually initiate regen?

To perform a manual regen, you must park the vehicle safely in a well-ventilated area, shift to neutral, set the parking brake, and turn off other accessories like the Jake brake and cruise control. Then, locate the dedicated regen switch on the dash and press and hold it for a few seconds until the engine RPM increases, indicating the process has started. Do not touch the foot pedals or turn the vehicle off until the process is complete, which can take 20 to 40 minutes.
 
This video explains how to perform a parked manual regen on a Peterbilt truck: 1mPrime Inc.YouTube · Jun 12, 2019
Before starting

• Park safely: Pull over to a safe, paved, or flat surface away from flammable materials and engage the parking brake. 
• Ensure engine readiness: Let the engine run for a few minutes to reach its normal operating temperature (at or above 185°F or 96∘C96 raised to the composed with power cap C96∘𝐶). 
• Neutralize the vehicle: Put the gear shift in neutral and turn off the PTO, cruise control, and Jake brake. 
• Do not touch: Do not touch the foot pedals, accelerator, or clutch once the process begins. 

Starting the regen

• Locate the switch: Find the manual regen switch on your dashboard. This may be a dedicated button or an option within the vehicle's settings menu on newer trucks. 
• Initiate the cycle: Press and hold the switch for about 5-10 seconds until the engine RPM automatically increases to a higher level, like 1100 or 1200 RPM. 
• Release the switch: Once the engine speed has increased, you can release the switch. The vehicle will typically show a light to indicate the regen is running. 

You can watch this video to learn how to initiate the regen on a Kenworth T680: 59sDouble D DistributionYouTube · Jun 25, 2024
During and after the regen

• Wait for completion: The process can take 20 to 40 minutes or longer, depending on the vehicle and conditions. Do not turn off the engine or interrupt the process. 
• Confirm completion: The engine will return to its normal idle RPM when the regen is finished. 
• Finish if needed: If the process is stopped, restart it as soon as possible. After completion, you can press the accelerator a few times to clean the exhaust system if needed.