Hello,
I found time to get in heart of engine (read: replacing all gasket related to timing cover). Let me share my experience (I am not doing this for living

Before you start job, please be sure that you have 10 mm thin wall socket. I took good hour trying to reach one screw with all possible imagination but I finally found one. Secondly, get organized - when you take part, take picture and put on some order. You can find a not logical screws on certain places. Remove upper torque mount (big peace of metal on left side) due to you are going get more space for some removal process. Once you start removal of back part of engine cover, screws, ....take some medication ..It would be too late to give up but you need time and a lot of (blind) work.

Now, I have everything a part and I have questions:
- when I put gasket, do I need use seal (FCP kit is coming with both gasket and seal) or gasket is enough ? I was told to use either but also, somebody told me that put gasket first and seal second. It is big question for me

- is any extra part should be replaced while I am doing this ? I am going clean injectors, replace spark plugs but I am asking about some sensor etc

- I got code P171900 (throttle position sensor) and I am wondering if it is part of throttle body

I appreciate your help ....

A.

 

Throttle position sensor is attached to throttle body.

Your code is for the transmission control module, I think. https://www.dtcdecode.com/Volvo/TCM-P171900. Word to the wise: Don't work on the car (at least, not seriously) without disconnecting the battery, and don't start the car until everything is reconnected properly. The 2007- Volvo S80 reminds me a lot of a Lincoln I rehabbed for my son to drive -- that car had a persnickety sensor network. It was by far easier to power everything down at the battery before working on it than to chase down electrical gremlins coming from transients flicking across various circuits for various reasons if I did any serous work on it with the battery connected. I learned to live with resetting the radio etc., it was far easier to do that than it was to troubleshoot stuff that went haywire because I unplugged whatever while the wires were 'hot.' Hey, it's a Fjord...

 

If I understand correctly, the issue is related to throttle body and I need replace as kit (as I know position sensor is not sold separately. The code (and your answer) is confusing me. If the position sensor is bad, I assume the signal sent to transmission is going be wrong as well. In the process of rebuilding car, I removed throtle body, cleaned but I didn't open 'electronic' part.

As for your advice for disconnecting battery, it is too late but I am going do it today. I focused on gasket and transmission and forgot about battery

If you are in in my position, what you are going do next ? Do I need replace throttle body (600 USD) or just cleaning would be enough.

I am tackling so many things in same time and if the car runs OK, I cannot give correct answer what was the problem ...

A.

 

No problem.

Throttle bodies **rarely** need to be replaced. You might have to replace some components of it, like the mass air flow sensor, or idle air control, or something. Simply cleaning it first, is a very good thing to do and might well fix the issues. Before you clean it, get replacement gasket because to clean it properly you have to take it off.

You *might* want a good used TB from ErieVoVo (erievovo.com), get that and clean it up then install it.