Tried to start the car this morning and click click click - put the charger on and got it to the point it wanted to start, was turning over nicely, but never started.

Given the battery symptoms, I purchased a new battery - Turns over great but wont start.

Immobilizer was on once but went away - now the reduced engine performance message is on.

We tried lock/unlock with door control and key fob multiple times
Tried starting neutral

Net searches yield little results for this so I'm still stumped.
I do have Vida software but cant hook it up until this evening.
No check engine, no codes from a standard OBD reader

Ran fine yesterday
And of course, we just sold her C70 Thursday - Murphys Law in full affect

 

Even though I technically put this in the wrong forum, thought I'd update anyway.
My XC is an 03 -

No idea why the timing of the battery failure caused this but ultimately found my fuel pump is not working.
Fuse is good - 12v at relay - 12v at pump and sending unit
No noise whatsoever from the pump

Amazon has the best price for a Bosch replacement.
$200 for the pump, two o-rings and the socket tool to remove the ring

 

Well, good job on your troubleshooting!