“Exhaust Filter Full” in your Dodge RAM – What to Do?

A Ram truck can throw the “Exhaust Filter Full” message on your dash when the DPF is overloaded with soot. Usually, this message only means this and shouldn’t bother you in any other cases.

Exhaust filter full message highlights

• Common reasons:DPF is clogged
• How to fix:run regeneration, have the DPF cleaned professionally
• Possible consequences:engine may go into limp mode
• Priority level:High
• Can you drive?Yes
• DIY repair:Possible
• Repair price range:$150-$1,500

In this article, I will tell you more about the following:

• Why can the particulate filter and selective catalyst reduction system get clogged?
• What should you do immediately when you see this message?
• How to manually start regeneration in your Ram truck?
• Regeneration passed but the check engine light is still on - why?
• What to do if nothing helps you deal with the problem?

Let's get started!

Why are DPF and SCR clogged in your Ram truck?

Modern diesel engines of any kind come equipped with several emission control units. The first one is the DPF. Also, there is a part just like a catalytic converter in a gas car called SCR or selective catalyst reduction system. And there are EGR valves and systems that burn more gases during the combustion process.

All of these systems are highly unreliable and will only work well under certain conditions. First of all, you need high-quality fuel. Secondly, everything in your engine should work well. If you've been observing the check engine light for two months without even getting curious about it, things shouldn't surprise you now when you get the "Exhaust filter full" message.

So, here are the primary reasons for DPF getting clogged:

• you mostly have short rides without letting your engine work for some prolonged periods of time;
• something is wrong with the ignition or injection in the vehicle, a lot of unburnt diesel fuel gets to the DPF;
• the DPF is old and damaged, it's clogged with soot that is impossible to clean out with simple regeneration;
• you don't allow the vehicle to complete the regeneration when it starts the process;
• the truck is primarily used as a daily driver without getting any load on the engine.

You see, every vehicle is made for certain purposes. The Ram truck, especially the Ram 2500 or another heavy-duty model is made for towing and hauling things. It should get some load on the engine, otherwise, there is no chance for the exhaust system to get cleaned naturally.

Over time, the soot that is inevitably formed when the engine burns diesel fuel is all dumped in the DPF. It can only burn there when the vehicle is under good load and the DPF heats up properly. This is actually what the regeneration is all about.

So, when you see the "Exhaust Filter Full" message in the dash of your Ram truck, it means that it's time to let the vehicle clean the DPF.

What should you do when you see this message?

Well, driving further without any changes in your behavior is a pretty bad idea. After several hours or minutes, depending on your luck, the Ram truck will most likely go to limp mode. It means that you will be able to drive with a restricted speed which can be as low as 5 mph.

The limp mode can be bypassed only after the regeneration is completed. So, the best strategy after you get this message from your truck is to actually help the vehicle complete the regeneration process. But how?

How to clean the DPF in your Ram truck?

There are two common ways you can help your truck in this situation. The one is relatively expensive, the other is almost free. Let's look at both of them.

1) Going to the dealer for controlled regeneration

If you come to a Ram dealer with this problem, they will offer one simple solution. The mechanic will take the original Ram scanner, plug it into your vehicle, and let the software do its job. This will take about one hour or sometimes longer. All this time, your car will be controlled by the scanner that will rev up the engine and heat the DPF.

You will lose some fuel and then you will also need to pay for the service. I called several Ram dealers and no one could tell me how much it costs. So, I believe they will charge some decent sum of money for this.

2) Activating regeneration on your own

Unfortunately, all modern Ram diesel trucks come without the possibility of launching the regeneration process manually. You will need the original scanner for this. But you can trigger the regeneration by driving your truck in a certain way.

I see several options:

• Drive in manual mode using lower gears and higher revs. Keep the revs above 2500 RPM and drive like this for about half an hour. The filter will start cleaning itself. Also, you may want to go on a highway for this.
• Get a trailer and drive on a highway for one hour. When the heavy trailer is attached to your Ram, the engine gets proper loads and heats up the DPF. This helps the system to get cleaned naturally.

Actually, even just driving on the highway at high speed or at least at high revs will help you in the majority of cases. But there is one problem - the vehicle may still go into the limp mode and require going to the dealership. So, I don't recommend driving far from the nearest Ram, Chrysler, or Dodge dealer.

Regeneration passed but the check engine is still on

After you choose one of the possible solutions and have done everything as I told you above, you may check in the on-board diagnostic system in your Ram that the DPF is not full anymore. If it shows 60%, for example, it's OK, the vehicle will work well and won't throw that message anymore.

But the check engine light is still on the dash - why? Well, the Ram truck will need some time to get rid of that light. Usually, it takes about three cold start cycles for the ECU to realize that there are no problems anymore. So, you will just need to wait several days for that check engine light to stop spoiling your mood.

Alternatively, you may ask the dealer to clear the error codes with the scanner. But this is yet another service you will need to pay for, so I strongly recommend you wait for some time.

What to do if nothing helps you get rid of the message?

If the "exhaust Filter Full" message keeps torturing you and you can't find any good solution for it, it's time to go to the dealer or to any good and trusted independent shop. You can fail to launch the regeneration properly and the filter may still be full of unburnt soot. Or there may be a problem with the DPF.

In these cases, you may need professional help. Although I usually hate dealerships and almost never recommend them to you, in this case, I would go to a Ram dealer and ask for the proper inspection with their original scanner. Also, this scanner can launch manual regeneration.

But before you agree to any repair like DPF replacement or something, ask them about the total price of such repair and inquire in other places like independent shops whether they will charge you less money for the same job.

Actually, if there is an expensive repair offered by the dealership, I would have the car inspected in some other place to make sure everything is correct.

How can you avoid clogging the DPF in your Ram truck?

There are several things you may want to do with your truck regularly to avoid issues with the DPF.

Here they are:

• sometimes, you will need to take it for long rides (100 miles and more);
• try driving at higher RPMs sometimes - make it more aggressive and active;
• buy only high-quality diesel fuel - this will save the truck from several problems;
• don't ignore any messages and lights that cover the emission system problems.

Final thoughts

I believe you should know something about how diesel engines work if you own one. Learn more about the DPF system and the ways it goes through regeneration. Make sure you understand what exactly you should do to let the vehicle clean the DPF on its own and not bother you with error messages or warning lights.

If you still have any questions, just ask them in the comments below!