I too have an 09 XC70 which is showing this odd behavior. I have been driving the car occasionally as we drive the 07 V70 every day. So I washed it and waxed the cross country and in order to reach the roof I had all the doors open. And I did not shut off the dome light. Anyways, I drained the battery so low that the in dash key fob would not release. Not finding the jumper cables, I brushed the corrosion off the terminal on the battery with an old toothbrush. It was mostly powder.

Since the 12V car charger, no snickers please, did not charge after 15 minutes of playing with that nonsense, I called the towing guy and he had the car started in a jiffy for a nifty fee.

I let the engine run for 20 minutes and then realized that while there was stereo, there was no turn signal or speedometer, so I drove it to my Volvo spa. The intern was nice enough to allow the Volvo master mechanic to turn it off and on. They said the system "relearned" and all was right. And that the system was in triage mode. I tipped the intern and was relieved to have a car for the weekend.

So today, when I intended to take my ward for the usual afternoon walk, the fob was sucked in and there was a clicking sound and I experienced that sinking feeling when you have left out no mistake in the arc of battery charging, tow service call, independent Volvo spa experience.

There were also weird code messages about the park brake which I never use and the front and back lights seemed to be lit weirdly as well. It certainly has been a moment to rethink the entire Volvo wagon experience. I really just want the damn thing to run and not be too complicated. Also the manual had nothing to say about seized fobs. I had to play with it like a cheap pin ball machine to get the key out. So alternator or battery or just go and buy a CAMRY and say goodbye to the full time job of babying Volvo wagons?