I took my 2017 XC60 in for this issue for the second time 2 days ago. Both times their diagnostics said nothing was wrong. When I drove it in 2 days ago, the airport temperature was 89 degrees and the temp on the dash said it was 102 degrees. This dealership is next to the airport. Again their system said there was nothing wrong, but they replaced the sensor just in case.
Is this common?
They gave me a loaner 2015 V60 and it read almost 10 degrees high.
I'm not driving much right now, but we'll see if it's really fixed soon.