Volvo Regen Problems Common Causes And Solutions

Volvo regen problems happen – and they are not quite rare.

Basically a regen happens when your DPF burns up any soot buildup off its face, which helps to prevent blockage and clogging issues. Your vehicle may also be carrying out passive or active regens.

Passive regeneration is the most common, and it occurs when your vehicle is in motion, as the heat of your exhaust burns off the soot out of the DPF. As for the active regen, this happens when there is not enough heat to your exhaust, which makes it unable to eliminate any soot buildup. 

Hence, your engine injects some fuel into your exhaust stream to boost the temperatures. Then, the greater heat helps to burn away fuel and soot.

But if there is failure in both active and passive regenerations, and you have some clogging risks to the DPF filter, the system will then generate a forced type of DPF regen. When this happens, you need to pull over, and this leads to some downtime, which can be quite frustrating when you have a schedule to follow.

On the other hand, failing to pull over increases the likelihood of damage not only to your DPF but also to your engine. And worse, your vehicle can go into limp mode. Either way, it will cause downtime, which is why you would like to avoid experiencing regen problems with your vehicle.

Find out why Volvo regen problems happen and what you can do about these. Let’s get started.

volvo regen problems

Causes Of Volvo Regen Problems

When there are issues with your vehicle, you should be able to know right away with the help of the check engine light and your dashboard instrument cluster’s gauges. These are good indicators that will let you know of potential concerns.

Now, let’s take a look at the most common reasons why you encounter Volvo regen problems. Here they are:

1. Hydrocarbon doser malfunction

Your hydrocarbon doser is responsible for injecting a small amount of diesel into your exhaust when forced regens or active regens are happening. Thus, it creates just the right amount of heat required to burn off the accumulated soot in your DPF filter. However, when your doser is clogged, this can prevent an increase in temperature needed for a successful regen.

2. Turbocharger problems

Your turbo is responsible for pushing compressed air into your combustion chamber found in the engine. What it does is to boost fuel efficiency and power to your internal combustion engines. To enable a regeneration to take place, your turbocharger would need to produce the right amount of heat that will trigger the process. 

On the other hand, if you have a malfunctioning turbocharger, this can prevent a regen from happening, which will eventually lead to a DPF failure.

3. Clogged DPF

As time passes by, your DPF filters tend to get clogged up with ash and soot. Thus, professional cleaning is needed to get this problem fixed. When you have a DPF that has been clogged prematurely, the filter is unable to get hot enough, which prevents it from burning the soot off when regular regens are happening. 

You need to get this issue addressed immediately since pressure buildup will cause your DPF to crack. It is important to pay close attention to signs of DPF filter clogs such as frequent forced regens that are unusually long and frequent. Keep in mind that it takes less than 40 minutes for a standard forced regen to complete. So, if yours take over an hour, then this is a sign of a problem.

4. Blocked DOC

Your diesel oxidation catalyst is the initial filter in your aftertreatment system. It holds a metal catalyst that helps in oxidizing hydrocarbons, unburned fuel and oil particles and carbon monoxide in your exhaust stream. When the inlet face of your DOC is clogged with too much carbon buildup, this leads to a back-pressure and prevents the smooth flow of exhaust into your DPF.

5. Faulty temperature sensors

Another cause of Volvo regen problems is having some issues with your temperature sensors. These spread through your aftertreatment system and measure the amount of exhaust that enters and exits through your filter. There is a sensor in the DOC and also in the SCR. When your sensor is faulty, it is unable to measure how well your system is working throughout the process.

6. DPF pressure sensor problems

This is an important sensor that monitors your soot levels of the sides of your DPF filter. Moreover, this measures the pressure drop and sends the differential pressure readings to your ECU. When you have a faulty sensor, this causes the ECU to receive false data and result in unnecessary regens.

7. EGR fault codes

Your exhaust gas recirculation system (EGR system) returns some exhaust gas back to the combustion cylinders of your engine. It also controls temperature and minimizes NOx emissions. So, if your EGR is showing some fault codes, this will inhibit DPF regens.

What You Can Do

If you experience some regen problems with your Volvo, the best thing to do is to take your vehicle to a repair shop and have a professional check it. When you do something quickly to get the issue addressed, this helps to prevent the problem from getting worse. 

This is why at the first sign of a problem, you need to pay attention and take action right away. Your gauge cluster tells you when there are issues occurring during a DPF regen. Additionally, you should take a look at your check engine light, which lights up when the regen process – whether active or passive – has been disabled.

With all these things in mind, it is best to be observant of potential issues by looking at the signs we have mentioned above and determine the best solution to your Volvo regen problems – which a professional can help you with.

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