PSA: FYI if your radio is constantly rebooting or resetting when connected to a phone via Bluetooth

This problem started for me with my iPhone running iOS 14.4.

The problem is that the phone will connect to the car, and then the radio will immediately reboot. After it does, the car reboots again once the phone is connected again.

It turns out the issue is that the infotainment unit for many Toyotas— I have the smaller screened version on our 2020 XLE AWD-e — has issues with syncing contacts. Not everyone has this problem, of course. It’s either something in the information that’s attempting to be synced, or the number of contacts. Occurs on iPhones and Android devices. The problem didn’t happen for us until a recent update to iOS and/or adding some contacts to my phone.

The solution is to delete the phone from the radio. Then when re-adding it, click no when it asks you whether to sync contacts. You may also be able to fix this by going to the car in your phone’s settings and turning off syncing of contacts (I.e., instead of deleting the phone from the radio and readding it.)

Or just don’t connect your phone to the car via Bluetooth after deleting it from the radio, which is what I did. We use CarPlay exclusively, so there’s no need for the Bluetooth connection.

I’m posting this as a PSA... there are some older threads regarding this issue, but for some reason they didn’t pop up during my Googling. Instead I found the answer on a Tacoma forum.