Using the iPhone with integrated in-car Bluetooth

Q: I read your article about iPhone integration in the car, but it didn’t answer my specific question. I have a Toyota Prius with integrated Bluetooth, and I know that the iPhone can pair with it, but I’m wondering if I can pair my iPhone to send and receive phone calls via Bluetooth and ALSO use the AUX port to play music through the headphone jack. If I plug in the AUX cable, will it play music and phone calls through the cable? My only concern with this is that my car’s microphone won’t be be taking in audio and the iPhone’s built in mic will be. Any ideas would be appreciated.

– Casey

A: For all intents and purposes, the Toyota Prius and most other in-car Bluetooth integration systems work with the iPhone in the same way that a standard Bluetooth headset would.

When using both a connection to the headphone port and a Bluetooth headset, the Bluetooth headset connection will normally override the connection via the headphone port for any outgoing calls, and any incoming calls that you answer with the headset (or in this case, via the Prius’ built-in Bluetooth feature). Note that if you answer an incoming call with the iPhone itself (ie, by touching the screen directly), the incoming call will be directed to the iPhone’s internal speaker and mic, or a wired earphone/mic unit if one is plugged into the headphone port. You can transfer this call to the Bluetooth headset either by using the “Audio Sources” menu button on the iPhone’s screen, or a button on the headset itself, depending upon the model.

Note that if the Bluetooth connection between the iPhone and the headset (or the Prius in your case) becomes disconnected for whatever reason, then any incoming/outgoing calls will use the iPhone itself and any audio device connected to the headphone port. In your configuration, this means that you will hear audio through your car’s stereo (via the AUX port connection), and the iPhone internal mic will be used to pick up your voice.

If you want to avoid hearing phone call audio via the AUX connection, the better solution is to get a device to connect to the iPhone’s Dock Connector. Although there are not yet any iPhone-specific devices for this purpose, devices such as the Griffin AutoPilot (iLounge rating: B) generally work quite well for most users. You will receive a standard warning that the accessory is not made for the iPhone when you first connect it, prompting you to turn on “Airplane Mode” to avoid cellular interference, which is generally the primary issue with accessories not specifically made for the iPhone.

In the case of car accessories, however, interference is generally quite rare as the iPhone is usually not placed in close proximity to the speakers. In our own experience in various vehicles (including a 2007 Toyota Prius, in fact), no iPhone interference was heard when listening to music through the iPhone using the Griffin AutoPilot.