Thank you! That’s very helpful & what I’m looking for: information on the circuit so I can look for the likely culprit. I actually spent a few hours searching this forum but didn’t find any solid fixes, either the wrong year or guesses as to what it could be. But I did see a few other owners who...

1999 V70 base model, problem started about 3 years ago with 215,000 miles on the car. When really hot outside, the doors wouldn't unlock with either the fob or by double-rotating the key in the door. As soon as it cools, even with the AC on for awhile, they work again. This hot/cool problem repeated...