"DPF Service Required, Stop Engine" Error Message – What is this?

The "DPF Service Required, Stop Engine" error message is one of the three warning stages of a failing or clogging Diesel Particulate Filter.

Before we look at this and the other two warning stages, let us look at some DPF basics.

What is DPF?

Thanks to rapidly advancing technology, trucks come with new features every day. Auto manufacturers are engineering heavy-duty rigs to be more efficient, comfortable, and easier to handle. In every aspect, modern heavy-duty trucks are much cheaper to maintain.

One of these advanced technology features is the Diesel Particulate Filter, an aftertreatment device that collects particulate matter from diesel trucks. The DPF uses a substrate devised from ceramic materials and takes the structure of a honeycomb.

To minimize harmful emissions from diesel vehicles, the DPF collects and stores soot and periodically burns it off into harmless emissions. The system burns off this soot in a process called regeneration. Burning the collected particulates eliminates the black smoke you regularly see from diesel vehicle exhaust tailgates.

The EPA emission standards of 2007 require every diesel-powered vehicle to have this device.

The DPF is not a disposable device. A brand-new one could cost $3,000 or more. To ensure that this device never collects soot to the point where it needs a replacement, you should regenerate it regularly.

"DPF Service Required, Stop Engine" Warning Message

Your diesel truck has DPF warning signals that come in the form of lights or an error message. When your DPF collects enough soot to require a regeneration, it warns you in three ways.

The first warning comes in the form of a solid light. This is your first warning that your DPF needs to regenerate. When this comes on, you have some hours before the engine begins to de-rate. If you choose to perform a regeneration at this first warning, you should drive uninterruptedly on a highway. The truck will enter into a passive or active regeneration automatically.

The second DPF warning comes in the form of a flashing light. This warning is more urgent than the solid light. It means your truck needs a parked regen, and it needs it soon. When this comes on, you do not have much time to keep driving.

If the "check engine" light accompanies the DPF flashing light, you should find a safe place and park, then initiate the parked regeneration. In some trucks, this light comes accompanied by a beeping sound to ensure you do not ignore it.

The Last Warning Is the "DPF Service Required, Stop Engine" Message

Also called the "Stop Engine" light, the "DPF Service Required; Stop Engine" error message comes on when you have ignored the first two warnings. It means the Diesel Particulate Filter has finally clogged, and your rig is no longer operable.

You cannot, and you should not ignore this warning. You must kill your engine immediately and call for roadside assistance when it comes up. When it gets to this point, you may even need to remove the DPF and clean it manually.

Signs you are About to Experience a Complete DPF Failure

Before it gets to the point of issuing the "DPF Service Required, Stop Engine" message, your truck will show these symptoms.

• The "Check Engine" Light will Illuminate

A faulty Diesel Particulate Filter affects the normal functioning of the engine. As a result, the Engine Control Unit will sense and issue this warning when it clogs or goes bad for any reason. The ECU uses sensors to measure engine pressure before and after you perform a regeneration. If the pressure is not at its ideal levels, the system will sense a problem and illuminate the "Check Engine" light.

If you notice the "Check Engine" light illuminated on your dashboard, use an OBDII scanner to determine the cause.

• Reduced Fuel Efficiency

The DPF is an essential component that clears fumes out of your vehicle. If it clogs, these fumes cannot leave as fast as they should, affecting your engine's full performance potential and ultimately reducing fuel efficiency.

Part of the reduced efficiency is because of the clogged DPF. The system pumps more fuel attempting to burn soot off the clogged filter. The other reason for the increased fuel consumption is that the engine burns more fuel as it strains to attain its full performance potential.

• Poor Engine Performance

Like the human brain, when there is too much work left undone, the backlog affects the person's overall performance. When the Diesel Particulate Filter clogs, it is hard for the engine to push out fumes. As a result, pressure builds up in the system and affects the engine's performance.

The backlog of fumes makes the engine feel weak and sluggish. The more exhaust gases build up in the system, the harder it becomes for more fuel to enter the engine. This makes acceleration a struggle. The problem worsens until your rig can no longer accelerate, triggering the "DPF Service Required, Stop Engine" message.

• Strange Odor

When the Diesel Particulate Filter clogs, it causes trapped exhaust gases to build up. You know the situation is bad when you notice foul odors in your rig. These gases are not just bad for your comfort but also your health.

The reason your diesel truck has the DPF is to clean these gases before they exit the exhaust system. If you notice this terrible odor, you are inhaling the fumes before the DPF can clean them. Moreover, these gases are flammable. They put you and your truck at risk of fire.

• Your Engine Will Not Start

You will not notice this symptom until the "DPF Service Required, Stop Engine" message shows up. When this message shows up, and you park your rig on the roadside, it cannot start again until you regenerate the DPF. The truck refuses to crank over because of the pressure backlog in your engine.

Although this can cause inconveniences, it is more of a safety measure than a problem. The engine refusing to ignite is for the safety of your vehicle. It protects the engine from the potential damage that could occur due to the collected fumes mixing with the ignition. You have no option but to bow to the pressure of the required DPF regeneration.

• Damaged Turbocharger

This is more of a consequence than a symptom. When you delay the DPF regeneration, the pressure build-up also puts the turbocharger at risk. When a clogged DPF hinders or slows the flow of exhaust gases, it causes the temperature to rise. Moreover, if you do not resolve the problem quickly, it spreads to the turbine housing and increases its temperature too.

If you leave this problem to run for a long time, it can damage the turbocharger. The "DPF Service Required, Stop Engine" error message signifies that you left this problem unchecked long enough. If the turbine housing gets extremely hot, it can leak and cause the overall performance of your truck to drop.

How Much Does it Cost to Replace the DPF?

A brand-new DPF could cost between $1,000 and $7,000. These components are not among the cheapest, which is why you should pay close attention to their maintenance. Most drivers execute the regeneration process when the truck asks to avoid these heft costs. In addition, you can clean it if it gets to the point where regeneration fails.

History has proved that these components rarely fail in newer vehicles. Your truck must have traveled for miles before asking for a DPF replacement. If you drive an older vehicle, replacing the Diesel Particulate Filter may not make sense. After all, the price of a brand-new DPF may be more than the value of your car. If you maintain your DPF properly, it will require physical cleaning every 100,000 miles.

Conclusion

The "DPF Service Required, Stop Engine" error message will not show up unless your truck is in dire need of regeneration. This warning comes up when you have ignored all signs and your DPF is now clogged. At this point, you cannot drive your rig. You have to park on the roadside and call for assistance.

This problem occurs because your DPF has clogged. However, before it reaches the point of total failure, your truck will issue some warning in the form of symptoms. These signs include reduced fuel efficiency, poor engine performance, foul odor, and the "check engine" light.

When you see these signs, you should act on them quickly and perform a regeneration to avoid the inconvenience of a failed DPF. If you drive a small car, you can clean the DPF and install it back. However, if you own a heavy-duty rig, you can replace the DPF with a new one.