"Manual Regeneration Not Allowed" Freightliner – What's the Problem?

Driving a Freightliner may sometimes be really hard given the modern truck will always bombard you with tons of errors and messages that you often just don't have the opportunity to read. And the "Manual Regeneration Not Allowed" message is one of the most pessimistic ones. Why? Because it promises you will have a lot of problems with the truck.

Today, we'll tell you more about the "Manual Regeneration Not Allowed" message in a Freightliner truck and why it may appear on the dash of your vehicle. We'll also look at the possible ways to deal with the problem and some important measures you can take to avoid this problem.

Here are some of the most important topics we'll be talking about:

• The "Manual Regeneration Not Allowed" message nature in the Freightliner.
• Will the engine derate after the regeneration is impossible?
• What are the primary reasons the regen is not being completed?
• How can you solve and avoid this problem in your Freightliner?

Let's get started!

What should you know about the regen error message in the Freightliner?

Modern semi trucks are more eco-friendly than older ones because they have loads of ecological equipment. But there is another side to all these ecological improvements - they create problems for drivers. Usually, about 90% of error messages you will see in your Freightliner truck within the first 3-5 years of use are connected to ecological equipment like DPFs, EGRs, catalytic converters, etc.

The "Manual Regeneration Not Allowed" error message may not seem that scary when you see it. It's usually displayed in yellow color which means the error shouldn't affect the way your vehicle works. But after that, you'll also see the red error message saying your engine will derate in a certain period of time. And this is a problem.

Here's how it usually happens:

• suddenly, your dashboard says that the manual regeneration is impossible to complete, before that the vehicle may have told you that you should press ON to start regeneration;
• the yellow message is there for a while and then it goes off and the vehicle may work for some more time as if nothing happened;
• but after that, the red error may flash showing that the engine will derate in 2 hours or in 60 minutes and you'll be able to drive at 5 mph only;
• also, the engine may just turn off unintentionally because of a problem with the DPF or any other ecological equipment;
• if you are in the middle of nowhere, this may be a great problem for you because you will have to spend a lot of time getting to the nearest repair shop or Freightliner dealer.

Well, the "Manual Regeneration Not Allowed" in your Freightliner is never the good news. You should be ready for this. And while it may seem impossible to avoid problems when you see this message, they are avoidable. Just read the article further and learn how you can trick the vehicle and get another 200-300 miles of normal driving.

So, the system works like this: it offers you to complete a manual regeneration process by just parking your truck and pressing a certain button. For some reason, you don't do this and eventually get the yellow message saying that the manual regen is impossible at this point. After that, the engine will derate and you will end up having huge problems on the road. Let's see why it happens.

Why is manual regeneration not possible in a Freightliner?

In most cases, the "Manual Regeneration Not Allowed" will appear after your vehicle has asked you several times to turn on the manual regen mode. Very often, this happens after your truck idles for an extended period.

For example, you may have stopped to sleep in a very cold place and don't want to turn off the engine. The engine keeps on idling to warm up the cabin for 8 hours. Chances are that within this time the Freightliner will ask for manual regeneration because the DPF may get clogged when the vehicle is idling.

If you don't turn on the manual regen just because you are sleeping, the vehicle will shut off or keep idling until the DPF is overly clogged. At this point, the vehicle will send you another message saying that "Manual Regeneration Not Allowed" and shortly after that, you will also get notified about engine derate.

Now you know how it works and why it may happen. But this is just one of the possible scenarios. Often, a vehicle may have also been driving slowly, so the DPF wasn't clean naturally. This may have caused some problems with the DPF like clogging or even damage. So, this error message may also mean that the DPF will have to be replaced.

Solving the Manual Regeneration Not Allowed problem in the Freightliner

First, we'll tell you how to solve the issue. Unfortunately, you will not be able to just turn the engine off and on again to reset the error. The clogged DPF will immediately activate the error message again and you'll have to deal with it somehow.

First of all, look how far you are from the nearest Freightliner dealership or specialized repair shop that may help you. This is the best solution because dealing with the problem without any diagnostic equipment is close to impossible.

Also, you may try to drive as close to the nearest city as possible. Then, you will be able to call for help. Numerous companies offer repair of semi trucks right on the road. You will just need to give them your location and they will send a specialist with all the needed equipment. But if you are 400 miles from the city, the price will be huge. If you are near this city, you will pay a good price for solving your problem.

Here are some of the possible things you will need to have done:

• reset of the electronic control module and activation of manual regeneration;
• manual cleaning of the DPF;
• replacement of the DPF;
• deactivation of some of the ecology modules to keep driving to the nearest dealership.

In most cases, you can do nothing by yourself and you will still need a specialist who can help you. But there is one trick you can use to save yourself from this problem and from additional costs.

How to avoid the "Manual Regeneration Not Allowed" error message?

If you own a Freightliner, the best thing you can do is buy a special diagnostic tool that can reset the codes. Also, you will need a smartphone with a special app to use this tool. So, this is not something too technical and anyone can do this with proper guidelines.

You only need to know where to install the diagnostic tool or scanner and how to reset the error messages and codes. Once you do this, your truck will need another 100-200 miles to measure everything and send another error message.

So, you will have some time to drive to the nearest Freightliner dealer. If the message happens to pop up again, the best thing you can do is to reset it once again with your scanner tool and drive another 100 miles before it reappears on the dashboard.

This is the easiest solution that will cost you about $100 for a decent scanner tool. And it will save you thousands and also hours of your time.

Why can regen problems just block your Freightliner?

Freightliner struggles to keep its trucks in the market and still equip them with diesel engines that are not considered really eco-friendly. For this, they need to invent new technologies that improve the overall efficiency of dealing with exhaust gases. If they don't do this, the current emission control rules will not allow you to drive the new Freightliner at all.

So, every two or three years we get some new emission control technologies that make the engine less and less reliable. This is the road to hell for owners and drivers of semi trucks but we can do nothing with this.

So, you just need to be ready to trick your vehicle and reset the error to avoid engine derate. If this happens, you may be able to drive at a very low speed only and this will make it impossible to get to the repair shop on your own.

Final words

We perfectly know that Freightliner vehicles are really durable and tough. But the problem is that they have to be eco-friendly and this causes a lot of issues when you drive them. The "Manual Regeneration Not Allowed" message is one of these common problems. If you see it, be ready for engine derate and all other possible consequences.

To avoid the message, just complete the manual regen as soon as the vehicle asks you about this. If you miss this message about manual regen, the DPF may get clogged pretty fast and eventually die. You will have to spend thousands just because you didn't press the button when needed.