Those are detected and reported at the dashboard console with a Check Engine alert.

How does the engine do in P or N? racing up the RPMs....any lag?

There's a possibility that the rock hit the drive train (angle gear, prop shaft, Haldex-rear-differential) and put it out of...

I haven't had that exact problem. But, the fault to concentrate on is the door-open sensor. Why?...because the other glitches are related to it either in software (the other functions are ...

The flaky electrical connection is your major clue. I think you need to get to the root cause of it. I take it you bought an aftermarket fuel pump....if you compare the harness connector fit on...

When's the last time you put in spark plugs? How old are your coil packs? Air filter?

When you're parked, how fast can you build RPMs? If it's got a lag, I'd be viewing traces on engine...

There is no such thing as zero oil consumption. You're likely down a quart at the oil change, or you topped up. 1 quart consumed over 7500 miles is the mark of a quality engine, at 90,000...

If you can't find a discrete fuel filter component, then you have a mesh intake filter bag internal to the fuel tank. It's not meant to be replaced.

Spray some clear water on a surface patch. Come back in about 5 minutes.

NO CHANGE
Vinyl does not absorb water, it repels it. Therefore, there is no change to patch from just after spraying...

Don't try to guess your diagnosis. Just to own this car, you should have a Volvo-specific OBD-II scanner (or VIDA / DiCE laptop app). Get a fault-code dump from the TCM.
You need a scanner that...

Yes. To test the AWD, you want to park:
front wheels on a slippery surface (ice, wet leaves, or 2 layers of wetted or frozen-soaked cardboard)
rear wheels on dry surface with good...

When you fill the tank 100%, do you get raw gas leaking out?.....You should be able to see a gunk trail where the leak point starts.

When I got my smoke test at a repair shop, costing $145,...

It's more likely a crack formed in a plastic weld, where a hose bib attaches to the tank.

I went from a 2004 XC70 T5 --> 2015.5 XC70 T6, and have been very satisfied. There were many enhancements in the years 2008-2016, which you'll want to learn about.

More notes here:...

Based on the hot/sweet smell, you likely had a boilover. There is a pressure release valve (I think built-into coolant reservoir cap) which would have gassed off to prevent hose rupture.
The steam...

Was it steam (hot vapor) or condensation (cold)? I think you would have smelled antifreeze if there were coolant leak. Check your coolant reservoir level -- are you losing coolant?

109C is very...

If there is a junkyard you can go to, I would try to get the tailpipe there. Then take it to a muffler shop for the welding on/rubber hanger.

Rodents can get into tiny places....let's hope it's accident damage to wiring....more likely to be found.

This sounds like a CANbus glitch. The first thing the CEM does after start-up is to poll all the 40-or-so modules to assure each module is alive and serial communication is working. I believe your...

If I'm seeing the photo correctly, a steel support bar has broken for one of the heavier exhaust components (cat or muffler).

If that's it, a simple fix would be to go to a muffler shop, and have...

There is no "BSM" module. Check this out:

https://www.dtcdecode.com/Volvo/BCM-0074

The ABS Warning is lighting up because it takes input from the Brake Control Module. Problem isolated to...

I had to replace the same '04 XC70. I liked the 2013 XC70 T6 I bought for my wife so much, I had to get one for myself (2015.5).

Engine-wise, the I-6 engine -- developed jointly by Volvo-Ford --...

Most DIY owners of this generation of Volvos swear by investing about $100 in the 2014D VIDA / DiCE clone as their major diagnostic tool. The "shop manuals" are included on the DVD.
All the...

Is it possible the coolant has a tiny steam leak in the engine compartment, and it's entering the cabin thru the intake vents? If you keep the "recirc" ON (outdoor air closed), does it go away?
...

For a safety-minded company, the scissors car jack "system" provided for tire changes is IMHO a serious problem. First, as a midpoint lift point, the jack is lifting 1/2 the weight of the car...

Have you searched the used tire market? These tires are salvaged from car wrecks, and tire shops installing upgrades. You specify the tread depth to match what you currently have.