I have it 2001 V70 XC Turbo
I was only able to drive it 6 days after buying it and have been going crazy trying to figure out how to fix it for over a month now.
The codes that I've gotten are P04447, P0452, P0236, and P0237.. Two of those codes went away after I replaced the BTS (Boost Turbo Sylanoid)
The last 2 that are left say that I need to check the vacuum lines and/or fuel lines or the fuel pressure regulator but I'm unable to find it or a diagram of my particular car in order to check and fix said problems.. Can someone please help me with this? Im a single mom and I start a new job on March 2nd 2022 .. if I can get this running that is. 🙏 please help. Thank u for your time.
-Christine

 

Won't start - that means -
1. Starter won't spin engine over?
2. Starter spins engine over but won't catch?

Let's go with #2
None of your codes had/have anything to do with the car not starting. Stop replacing parts by code, it gets expensive and frustrating. 447 and 452 are evaporative emission codes - like your gas cap is loose, missing, a small vent hose is loose - none of which will prevent starting. 236, 237 are related to the boost pressure. The car will run without a boost pressure sensor or solenoid - it will not/can not turn off the fuel pump, spark or compression.

So - Engine needs compression, fuel at the correct pressure and time, and spark at the correct time. How did your car fail? Stopped running while driving or one random day just failed to catch when you tried to start it?

Start with the basics. What's the compression? Is the timing belt still there and aligned correctly? What's the fuel pressure? Do you have a spark at a/the spark plugs? (How much gas is in the car? -many times car were towed in because the fuel was low!)

You won't get a code for low/no fuel pressure, there is no sensor on your car. Throttle housings are a known failure on a 2001. They are drive by wire and have been known to not open when they are supposed to. Stuck Closed throttle plate = no air = no run (must have air, fuel, compression and spark) How old is your throttle plate? What color label does it have? Allegedly the "white" label throttle housing are the worst original ones, replaced by a "yellow" label housing. The factory yellow label ones lasted longer but still failed in the same manner.

 

Thank you for getting back to me. I went to start it one morning and it would crank but not catch. I have just under a full tank of gas and I've checked to make sure the gas cap is good and tight.
The day before it stopped running i had drove it through very deep snow for quite a ways and i was wondering if a hose maybe came loose.
I thank u for your time.

 

a displaced small hose like the Evap vacuum line won't keep the car from starting but if one of your intake air hoses from the turbo to the intercooler to the intake came off, then that could do it. A loose gas cap wouldn't cause a no start - all that would do is trigger an Evap emissions check engine light. At any rate, if you drove home after driving in deep snow, you probably didn't knock a hose off but something may have gotten wet.

 

fuel pressure regulator on the end of the fuel line may be bad. look up PEPERMINT VOLVO FUEL PRESSURE REGULATOR. peppermint knows all!

 

FPRs have a diaphram in them that can tear, which will allow the residual pressure to bleed out when the car is off (causing cold start issues) and can allow extra fuel to be sucked into the intake through the FPRs vacuum line. A quick test for a faulty fuel pressure regulator is to start the car to build fuel pressure then turn the car off and remove the vacuum line to the FPR. If gas leaks out, you likely have a torn diaphram and need to replace the FPR. Unfortunately its not the cheapest part under the hood so best to do some testing/diagnostics before swapping the part on a prayer.

 

That is very true and I have replaced many. The OP states he has a 2001 xc70 in the US - that engine has a non-return fuel system and the fuel pressure regulator is in the fuel pump assembly in the tank. There is not a fuel pressure sensor on the fuel rail on that year either.