Paccar MX - 10 Minute Parked Regen

In this blog we will cover what the “10-minute parked regen” is and why this occurs on your Peterbilt or Kenworth truck. 

A question that comes up pretty often is, ‘is there a way to manually regen a Paccar engine?' The short answer to this question is 'Yes!' But the truck has to allow you to do one.  

The parked regen is a process of self-cleaning of the DPF filter and you start this process by pressing the regen button located on the dashboard. However, your vehicle has to be asking for a regen or else it will not start.

You may also see a notification on your dashboard if you need to perform a parked regen.

The 10-minute regen timer is just a notification that a parked regen needs to occur. A parked regen is going to go through a full cycle to ensure everything related to the engine and aftertreatment system is working properly. The aftertreatment covers the EGR, DPF, DEF, SCR systems.  

What year truck and engines does this affect?  

2011-2021 Peterbilt models and 2011-2021 Kenworth models.  

• Engine: PACCAR MX11 or PACCAR MX13
• Emission Years: EPA10(2011- 2013) | EPA13 (2014-2016) | EPA17 (2017-2021)
• Equipped with DPF, DEF, SCR, EAS, PCI, EGR, VGT 

How long does a parked regen last on a Paccar MX engine?  

The parked regen is controlled by your engine computer and aftertreatment system. The truck knows it needs a regen and when this occurs it can last anywhere from 10 minutes to 1 hour. The temperature light on your dashboard may come on when the exhaust temperature is getting hotter as it is going through the regen process. 

What happens if I stop the regen once it has started?  

It is HIGHLY RECOMMENDED that you do NOT stop the regen once it is started. 

The reason you don’t want to stop the regen is because it will trigger a failed regen response to the engine computer and you will end up in a derate.  

If a parked regen does not start, there are 3 things you can do?  

1. It’s important you go through all of your system checks first. Make sure your engine speed is down to idle, ensure you have your parking brake set, engine brake switch is off and cruise control is off. Make sure you are not pressing your brake pedal or your clutch during this time. 
2. If you verified all the system checks are done, then check to see if you have an active ‘Check Engine Light’ on. You may have an active fault code that is preventing the parked regen from starting. This fault code could be the issue of why you are required to do a parked regen. 
3. Connect a diagnostic tool such as OTR Diagnostics or DAVIE to perform the troubleshooting and/or forced regen. 

Will a parked regen work when in limp mode or stuck at 5mph?  

If you are currently derated at 5mph with a red stop engine light on then you may have a critical issue with your DEF/DPF system. In this case you will not be able to perform a parked regen. You need to have a diagnostic tool such as OTR Diagnostics, or DAVIE to perform the troubleshooting and/or perform a forced regen. You can find more information about the Paccar DEF derate here.

Will I still be able to run a parked regen with EGR derate notification light on?  

If you currently have P1495/P1496 or SPN 1787 FMI 11 fault codes, then you will not be able to run a parked DPF regen.

This EGR derate will disable a driving regen and a parked regen. You need to have a diagnostic tool such as OTR Diagnostics, or DAVIE to perform the troubleshooting and/or forced regen. Here is a blog where we cover Paccar EGR derates in more depth.

NOTE: You need to make sure you are in a safe area away from other vehicles when starting a parked DPF regen.  

How do you start a 10 minute parked regen on your Peterbilt / Kenworth truck?  

1. Start your engine and let it idle.  
2. Make sure coolant temperature is up to at least 185 degrees Fahrenheit.  
3. Make sure your engine jake brake switch is off, cruise control turned off, ensure your parking brake set, and truck is in neutral.  
4. Hold down the regen button and keep holding the button down for at least 10 seconds.  
5. The engine RPM’s will start to increase from IDLE to a higher RPM. 
6. Remember, do not cancel the regen. Do not press brake pedal, clutch, park brake. 
7. A parked regen will take from 10 minutes up to 1 hour to complete. The engine RPM will come back down to idle once it has finished the parked regen. Make sure you leave your truck idling for at least 10 minutes to ensure that your engine and exhaust system cools down before you shut the truck off.  

I hope this helps with some questions that seem to come up!

Until next time! 👋
Stay safe, stay healthy & be blessed.