When Phone Not Recognized, Where is the Failure?

[PianoAl]

Our car will recognize my phone flawlessly for months but then fail to see it multiple times in a row. Recently, my wife and I were both in the car with our phones, but it still asked me to put the keycard on the central console to drive. I can always resolve it by futzing with the app or airplane mode, although once, I could run the app and unlock and lock the car, but I still could not drive (had to reboot phone).

My question: What is failing? Is the Bluetooth signal not detected by the car? Is the phone not doing the handshaking? Is the car in deep sleep?

 

[jmaddr]

Impossible to say. The only thing I think you can check is to go into your bluetooth settings and see if you have a device that looks like a jumble of numbers and if that device is connected. It should be. I'd likely say if a bluetooth toggle (like your airplane) or reboot of your phone fixes the issue, the issue is in the phone. I recently started having this issue after more than a year of stable use but I'm chalking it up to beta iOS 14 code.

 

[stevegu]

I have had this same experience, in fact, today and yesterday. Although bluetooth may be One such cause, it apparently is not the only one because both days I was able to open the car with my phone in my pocket, but was asked for the keycard to start driving. Bluetooth was active, connected, and with proper settings at the both ends (sometimes these inexplicably change in the car as well), but still it required more action. Yesterday I went ahead and used the card, today I opened the app on my phone and that seemed to work.

 

[Enginerd]

Initially when I got the car (2018) I would have occasional trouble with walk-up unlock (~20%). Then earlier this year, I can't remember exactly when, it became much more reliable. In the past couple of weeks, the reliability has taken a real nose-dive. I'm only getting the walk-up unlock about half the time. I do have an older phone (Galaxy S5), but the discrete changes in reliability suggest to me that it's something in the firmware (speculation).

Another recent issue is the app connection to the car. Previously the only times it has failed is when there is no cell coverage. Since about 2020.28.6, I'm even having trouble connecting at home, with my phone and the car both on a good WiFi signal. Sometimes it works, sometimes it just doesn't. Related?

 

[Dangerous Fish]

I've had this happen a few times very recently but never experienced it before, so I'm wondering if it's a bug introduced with a recent update.
I think it's a bluetooth related issue.
A reboot yesterday seemed to help. I'm on 2020.28.6

 

[smatthew]

This happens to me like twice a year. I just toggle bluetooth on/off in the phone. I assume the iOS bluetooth stack has gotten corrupted? It is funny that it will let me in the car, but not let me drive.
To be honest, my iPhone XS Max acts like a POC most of the time. I have to reboot it daily. I think I've dropped it too many times.

 

[Airgetlam]

I’m pretty sure that door unlock is in the BLE stack, and not the normal Bluetooth stack.

 

[XLR82XS]

Have you tried with only 1 phone in the car at a time? (i.e. wife's phone is disconnected/off/gone)
iPhone 7 here and zero issues with 3 Teslas.