SDP Malfunction Volvo – Causes And Solutions

You may have heard of the SDP malfunction Volvo trucks sometimes experience. 

Now, this may be a concern for some people, especially if there are warning codes present. The last thing you want is to notice anything in your vehicle is malfunctioning. ‘

With this in mind, let us take a look at the reasons why this happens – whether you can just ignore it or if you should actually do something about it. 

If this is something that concerns you, and you are wondering what maybe causing it and if there is anything you need to urgently do to resolve this problem, keep reading to learn more about the answers to these questions.

What Causes The SDP Malfunction Volvo Trucks Experience

We have heard of some people who have encountered an SDP malfunction on their Volvo with a Cummins engine and at only 70,000 miles. This can be quite concerning for some since that is most definitely not a lot of mileage, yet an issue is already showing up.

There are a few possible causes to this problem such as the front radar system, or could also be the front lens is covered. If so, then you will have to simply clean your lens. Otherwise, continuing to drive even with this problem may result in the cruise control failing. 

Another thing to keep in mind is that there should be other active fault codes. There may also be a huge amount of exhaust smell, which means you will have to get the engine checked. In some cases, doing this can help with the problem, and it should not persist anymore. But for others, it does not always completely solve the issue.

Either way, it is most definitely a good idea to visit your dealer when you notice an SDP malfunction issue with your Volvo, in addition to the radar system. Some of the codes that are linked to this are the IIRC and the SDP. So you really have to get these issues checked by a professional to avoid further issues from occurring. 

Other Issues with the SDP Malfunction in Volvo

There are a few other concerns linked with the SDP burner engine as reported by some drivers. For instance, they have  two SDP burner engines – one was 600 and with a double DPF while the other is 550 single. The 600 is pretty much a local heavy tractor that pulls a lowbed while the 550 one is over-the-road type for longer miles.

The injectors seem to work just fine for the most part, and they do pass every test conducted on them. But after a while, a malfunction started occurring, which could be due to a few problems.

One of the possible causes is a fuel pressure issue, which is why it is best to have the check valve checked and make sure that it really fits well. The engines typically run a higher fuel pressure because they provide fuel to your ARD head. 

Now, some drivers report shimming the relief valve at about 125 PSI. After checking the fuel issue and all of the 3 check valves are brand new, the data log appeared to be better. This is why it may be worth it to change the valves as this can sometimes address the injector problem.

You may also want to check the seat and see if it is warped. If so, then the needle tends to stick under heavy loads and high temperatures. When pulling the injectors, check to see if these are blue at the bottom portion or even halfway up. 

It is also worth noting that this issue tends to be a bit tricky to troubleshoot. It may be ideal to extend the clear lines or the sight glass, then tie to your wipers. This way you will be able to see this component more easily even under a heavy load.

Additionally, it may be worth it to check if there is a low pressure to the fuel system. If you have changed the 3 valves, there may be some restriction on the pump’s suction side, which causes the air in the fuel to cavitate. If you have a restricted or blocked fuel return line, this can result in extremely high fuel temperatures in your fuel manifold. 

Moreover, if the fuel return line stays blocked to your tank, there may be air bubble buildups in your fuel manifold. Any trapped air can lead to damage to the injectors for the 6,5,4 cylinders because the trapped air in your fuel manifold occurs on these injectors initially. 

But be sure to check the unit injector, anyway. If this is improperly or loosely seated, injector failure also tends to occur. This can also lead to failure of your O-ring seals, as well as leaking combustion gasses to your fuel manifold. Hence, damage to your injectors may further arise. 

Bottom Line

When you experience an SDP malfunction in Volvo trucks, this can mean a number of things that are worth inspecting. Consider checking the different relevant parts that we have mentioned to determine what is the actual culprit and what you can do to further eliminate this issue once and for all. When in doubt, it is always good to consult a specialist who can provide you with a definitive solution to this problem and prevent further damage to your vehicle.