Car stereo does not connect via Bluetooth after phone power-on if visibility is OFF

Bug Reports
#1

REPRODUCIBILITY: Always
OS VERSION: 4.5.0.24
HARDWARE: Xperia 10 III
UI LANGUAGE: Polish
REGRESSION:

DESCRIPTION:

After a power-off / power-on, car stereo is unable to connect phone.
Bluetooth is active, but car cannot connect.

I need to enable phone visibility for a moment and then car stereo connects without problem.

PRECONDITIONS:

  • Phone is fresh after power up
  • Phone is unlocked

STEPS TO REPRODUCE:

  1. Turn off phone
  2. Turn back on
  3. Wait until boot
  4. Enter lock code
  5. Start the car and wait until it tries to connect the phone
  6. Force car stereo to connect the phone

EXPECTED RESULT:

  1. Car stereo should auto-connect to phone via Bluetooth
  2. Car stereo should connect to phone via Bluetooth

ACTUAL RESULT:

  1. Unable to connect any phone
  2. “Phone is not responding” message

MODIFICATIONS:

None.

ADDITIONAL INFORMATION:

Works fine if the Bluetooth visibility was enabled. Even for a moment. You can enable visibility and disable immediately. Then the car stereo is able to connect without problem.

1 Like
#2

Hi,

Yes I also have this issue.
My Work around is get the Phone to initiate a connection to a blue-tooth device, after this it will then accept connects.

My car won’t accept connections it only initiates, however I have a blue-tooth heads set that both initiates and and accepts connects, therefore I get the phone to connect to those, then My car works normally.
Still an issue in 4.6.0.11

1 Like
#3

Bluetooth visibility is the way to control if surrounding devices can connect to the phone. Having the visibility turned off means that the phone can connect to other devices but other devices cannot connect to the phone. It is the tool to prevent connection attempts while being able to keep using Bluetooth (e.g. listening to music via a headset).

In this bug report, the Bluetooth system of the car attempts to connect to the phone. It fails if visibility is turned off. If visibility is enabled then the car can connect to the phone. The phone works in the way it is intended to work.

3 Likes
#4

I don’t think that’s the case here:

The car connects to phone fine even without the phone being visible, as the car already knows what the mac address of the phone is.

I believe this is the same problem that I have been having, and also many others. The bug has several symptoms, so the bug reports end up being a bit different as everyone describes the symptoms that they have noticed. See:

I myself used to suffer from this on 4.4, then I didn’t have it on 4.5 and now it appeared again on 4.6.

I spent quite a lot of time debugging this when I was on 4.4. The issue is, or at least it was then, that something rfkills bluetooth while it is being initialized. I couldn’t figure out what was causing it, but it is very timing sensitive - even small changes in the bootup sequence could change this, which is probably why I didn’t see it happen on 4.5. I believe it was just good luck, which has now run out. I haven’t really tried debugging it on 4.6, but the symptoms are really similar so I believe it’s the same bug.

4 Likes
#5

Thanks vige for a good summary. You must be closer to the culprit than I.

#6

I have filed an internal bug about this issue. The tag ‘tracked’ is set.

1 Like
#7

Me too, issue is back on 4.6.

#8

Your theory on a timing problem sounds reasonable.

BT connects fine from my VW Passat (model 2014) to my Xperia 10 III (running 4.6.0). The phone gets automatically connected.

#9

X10III, SFOS 4.5: after a fresh reboot the autoconnection to the car kit always fails.
As soon as I restart BT from SFOA utilities, it connects just fine, and quite quickly. Consistently observed since v4.5 on two distinct cars.

With other BT devices don’t display this behavior (tried several head sets and speakers) . I mean, they’re automatically connected after a fresh reboot.

It might be a timing issue in conjunction with specific devices (potentially BT stack & hardware from same vendor in several car brands )

#10

More testing in VW Passat with Xperia 10 III:

CASE 1: Xperia is powered ON and brought to the car. The car engine is started after which the car “Turns the telephone on” and searches for the previously used phone (Xperia 10 III):

My Passat automatically connects to the Xperia 10 III, whether restarted a moment ago or not, but on the condition that Bluetooth visibility is enabled. If disabled then there is no connection.

  • vige: I have paired the devices without explicitly giving the MAC address of my phone.

CASE 2: Xperia is powered OFF and brought to the car. The car engine is started after which the car “Turns the telephone on” and searches for the previously used phone (Xperia 10 III) but cannot find it.

If I turn the phone on now (and it has BT on and visible), the car does not find the phone as it does not run “Turns the telephone on” at this point and therefore it does not search for BT devices. However, if I run a manual search via the car UI, it will find the Xperai 10 III and connect to it.

1 Like
#11

My 10iii has a similar issue after the phone has been restarted or has previously been in Flight Mode.

To be able to get the phone to connect to my car I need to used the "Bluetooth Restart " option in the Utilities section in Settings.

Once I have done this the phone reconnects everytime until the next time I do a restart or use Flight Mode.

On the other hand my smart watch reconnects without having to use the Bluetooth Restart option.

#12

X10 III (was same with II): yes, post-reboot, I have also found I need open Bluetooth settings screen for phone to get connected. It’s like Bluetooth service doesn’t auto-start.

But writing this, I thought to check systemctl status bluetooth and indeed, somehow it had become disabled, with vendor preset enabled. Did I disable it at some point fiddling around…? Maybe. Either way, I’ll run another check on the next car ride.

#13

@jovirkku now check this scenario:

  1. Disable Bluetooth visibility of your phone
  2. Turn off the car and the phone
  3. Turn on the phone
  4. Turn on the car
  5. Bluetooth connection is not established
  6. Enable Bluetooth visibility of your phone
  7. Turn the car off and back on
  8. Bluetooth connection is established
  9. Disable Bluetooth visibility of your phone
  10. Turn the car off and back on

The expected outcome at this point is for the BT connection to be established automatically - at least that’s what happens in my case (Xperia 10 III and Seat Leon III gen.).
The issue is: the car can connect to the phone with BT visibility disabled but only after it has been toggled off and on once after phone reboot.

I’ll have to verify that, but I think that you don’t even need to be within range of the car when toggling BT visibility:

  1. Disable Bluetooth visibility of your phone
  2. Turn off the car and the phone
  3. Turn on the phone
  4. Enable Bluetooth visibility of your phone
  5. Disable Bluetooth visibility of your phone
  6. Turn on the car
  7. ???
1 Like
#14

After the automatic connection to the BT car stopped working in SFOS, I tried different scenarios. The result is like this (I read it here on the forum)

Xperia 10III, Mazda 3

  1. 10III is on, BT is off (not visible), Media app is on (to show me the song titles on the car screen), car is off
  2. turn on the car
  3. in the upper quick menu 10III, I hold my finger longer on the BT icon
  4. BT Settings - device search will appear
  5. my car will also appear in the list of found (paired) BT devices
  6. tap the car device to connect BT
  7. BT connection with the car works.
#15

On my Huyndai Tucson it’s a bit more complicated: After turning on the car, the car will attempt to connect to phone, which fails. The car will continue attempting, but it does not tell it to user. Have to press e.g. phone button on the Car UI, after that the car will show a dialog where it shows that it is attempting to connect. I have to press “cancel” there, and only after that try connecting from phone to car. Trying to connect from phone to car while the car is also trying to connect to phone will fail.

#16

Thanks Svistak, your procedures clarify this BT case a lot.

Yes. The car (VW) automatically connected to my phone after step 10. So, the visibility can be off, in principle.

At step 7, the car automatically connected to the phone.

CONCLUSIONS:

  • After restarting the phone, the car cannot connect if the BT visibility is off
  • After toggling the BT visibility (following a phone restart), the car can connect even if the BT visibility is off.
#17

Great!
You were faster than me :slight_smile:

At step 7, the car automatically connected to the phone.

This is what I expected, and suggests that after reboot something is different in the way the phone handles BT connectivity, than after toggling BT visibility off and on.

Next thing I’d (or anyone who is close to their car right now, as I am not) like to try is - instead of toggling visibility - disable and reenable the whole Bluetooth subsystem after reboot, then see if the car connects.

#18

It’s parked right outside my office so what should I exactly do?

Like so?

  1. Set visibility to: Off
  2. Reboot the phone
  3. Check if the car and the phone connect
  4. if not, disable and enable bluetooth
  5. Check if the car and the phone connect
#19

Yes. You can even omit step 3, as @jovirkku has already tested that.

#20

I went through steps 1 to 3 and the phone instantly connects so no point in testing 4 and 5 I guess.

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Playing music over BT works too.

Locking, unlocking the car work as well, but that’s Bluetooth LE, so probably does not require pairing anyway.

1 Like