Hello
I recently purchased a Volvo XC90 2004 Auto 2.4 diesel with 164000 miles. During driving (particularly putting extra strain on the engine ) a "engine service required" warning comes up and the engine loses power and seems to be in a limp mode. Sometimes it will clear whilst driving. In its limp mode I can change gears manually which helps. Does anyone know what may be causing this please? Many thanks
ps I ran a diagnostics check and nothing untowards showed up.

 

If nothing shows up during your diagnostics check, which I assume you are using a scanner, you will need something compatible that will communicate with all the modules in the car and see what codes are coming up. That light on its own can mean anything.

I assume there is no actual OBD2 code stored?

 

Did anyone get to the bottom of this as mine is doing exactly the same.
XC90 07 D5 2.4l
Many thanks

 

did you scan for any stored codes?

 

It could be the turbocharger or related parts causing the issue. If it's struggling to deliver the necessary boost under load, it could trigger limp mode to protect the engine.
Check the fuel system too, like the filter and injectors, for any problems.
Also, a faulty MAF sensor can mess up the fuel-air mixture, affecting how the engine performance.

 

Make sure you don't have any chunks missing from your plastic turbo air handler or whatever the plastic tubing is called. I don't recall if I ever got the "service engine" message, but mine was dying a lot while driving, and would start right back up. The guy I got it from had that same issue for months on end, and the dealership kept throwing parts at it to fix it, but never managed to fix it. They replaced the MAF sensor twice, the throttle body and all kind of thing without any luck. Turned out the entire issue was a chunk of plastic broken off by the driver side engine mount in a spot that you can not see unless you remove parts. Sucking in all that air through the broken section was killing my engine all that time. Replaced that and have not had a single problem with stalling out since then. I have read of others with that exact same issue as well.

Might not be your issue, but give it a look and see for sure.