The method used to recognize the USB device has a clever bit of code in the firmware to improve the connect time once the initial handshake with the device has been established. So after the update to iOS4, the host device (Car Stereo) still thinks that it is connecting to the un-updated client device (iPhone prior to updating to iOS4) The updated client device (Your iPhone with iOS4), must fool the host device (Your car stereo), into believing that it is an entirely new device. This is done by connecting your iPhone to the stereo head USB port with the iPhone switched off completely. This is achieved by holding down the top power button on the iPhone until the red slide bar comes up and prompts you to shut the iPhone down. Do this and then with the car stereo switched on, plug the iPhone into the USB socket and wait till the iPhone starts of it's own accord. If it does not start, press the top power button on the phone until it starts. This will force the host device (Your car stereo) and the client device (Your iPhone) to re-negotiate the handshake between the devices and get you back to where you will once again be happy.
Now we can all stop beating up both the Car Stereo manufacturers and Apple and focus on being civil gentle folk that enjoy discussions about how clever we all are to be able to use amazing technology to get ourselves over-stressed and irritable.
A friend of mine said he had to delete his iPhone from the devices list on his car's BT stereo and re-do the detailed setup as if doing so for the first time. That may be what the Alhedward was getting at - try and make the car stereo think that you're pairing up a new device.
BTW - thanks for that idea, Alhedward - you might have solved the USB issue I'm having with my car stereo. I'm going to go try it at lunchtime.
iPhone 3G, iOS4 and Toyota 2009 Nav system. Worked fine yesterday, borked today.
I deleted the phone from the Toyota and the Toyota from the Nav. No love.
While I love iOS4 I must have BT connection with stereo. Plus, it is not like I can expect a firmware from Toyota, so I need Apple to solve this ASAP.
Same problem with my bluetooth. On iOS 3.1.2/3.1.3 it worked flawlessly as soon as i upgraded to iOS4 it randomly disconnects and reconnects and I get a different voice message back from the car about connection established instead of connection complete
Kia Forte 2010 bluetooth handfree built in
I have a 57 plate 407.
Connects fine, but when the phone rings, the stereo goes silent (does not make the ringing noise) but also the phone only vibrates ( I presume it thinks it should be on silent)
also, none of the numbers come up on the screen.
very strange, but hopefully apple will sort it out quickly.
I also have this problem. I have an iPhone 3G S and I have the OEM Bluetooth module and OEM navigation on my 2004 BMW 330i. After updating to iOS4 I've had to re-pair the phone with my 330i's handsfree module.
The pair succeeds for a brief second before losing its pairing. The funny thing is that the Bluetooth icon on my iPhone shows up as being functioning.
Similar issue here: I am having a Peugeot 207SW, using the built in Bluetooth support for mobile phones. Everything had worked perfectly with earlier phones and then with my iPhone 3GS running on 3.1.2 and 3.1.3. However, since I upgraded to iOS4 I am experiencing serious problems:
-the iPhone randomly connects and disconnects
-sometimes the iPhone won't connect at all
-on other occasions when connected to the car via Bluetooth, the iPhone suddenly hangs and needs a complete restart
-one time during a call, it broke off and decided to play a loud annoying sound that could only be stopped by pulling over and turn the car on and off - seems like iOS4 has managed to crash my car audio!
All this is VERY annoying
If Apple doesn't fix this, I will have to downgrade to 3.1.3 again which has less eye candy but is free of those severe bugs...
Car 1: 2010 - VW Jetta TDI (Turbo Diesel) w/ Non-Navigation Audio BT Connection
Car 2: 2009 - Ford Escape w/ a Microsoft Sync Stereo system - No complaining about Microsoft here...Apple doesn't make a stereo ...but this is one of Microsoft's better product offerings.
Black MacBook - 2 gigs/ram, 250 gig HD, intel processor, etc...
Iphone 3GS - OS 4.0
Prior to the OS 4.0 upgrade my blue tooth phone book access, blue tooth music access, hands free phone use, was just fine....pretty much in both vehicles my iPhone 3.1.2 worked just fine....
Now with the OS 4.0 - Not so much. My iPhone will only connect the hands free phone component with either of my car's stereos. I can not get either vehicle to accept an Stereo Audio Blue Tooth connection so I can listen to my music and control it from my iPhone.
On top of that prior to the upgraded OS I had an iPod/iPhone connection cable in my Jetta and it worked fine in the past. (At times I would use it instead of Blue Tooth because I would charge my iPhone using the adapter) Now my stereo will work for for a few minutes but eventually locks up and will not allow me to switch between artists, albums, playlists, etc...it will only let me continue to listen the current selection of music. Now I get a message on my iPhone that says this device may not be supported...it never had an issue in the past.
So I feel that most people are coming to the same consensus that the new OS has altered something in the blue tooth handshake/coding....I have already read a few of the "Apple does no wrong postings..." please don't respond...your opinions are obviously biased because Apple is far from perfect...and you input rarely does anything to help. As for anyone else who has some ideas - other than downgrade you OS, I would appreciate hearing something.