[Q] Bluetooth and Cars topic

There are some very old threads about this - but this is now, pretty certainly, a general stock android 4.3/4 problem with "older" car hands-free systems. My kit is a Galaxy Note with OmniROM right up to date. My car is an Opel/Vauxhall Zaphira with a Navi 900 onboard computer. However there are threads on many android forums complaining of the same symptoms for "pure" stock 4.3/4 devices (e.g. the Nexus range, including the Samsung Galaxy Nexus) and a variety of cars, and all describing the same workaround (and a few lamenting that Google haven't been very responsive in addressing the problem). The symptoms and workaround are:

• The car recognizes and "partially" pairs with the phone


• However, the contacts list and call lists are empty and the phone cannot be controlled from the car, neither for incoming calls nor for outgoing calls (dialing from the car interface always gives a failed message, while trying to receive or hangup from the interface just plain fails).


• Calls using the phone work, and show up on the car interface, always as "Unknown" (not surprisingly - it doesn't have the contacts list)


• HOWEVER if, after this "partial" pairing up, I make a 30-45 second call using just the phone itself, then, after the call has terminated, contacts and call lists are properly available through the car interface and the phone can be fully controlled from that interface (and, of course, the FIRST time this happens, I get the notification on the phone telling me the car wants this information, which, of course, I confirm)

A workaround like that can be scripted with something like "Tasker" and using, say, my voice mail number (with my provider here in France, plain fake number calls don't stay online long enough for the above to work).

But does ANYONE have any idea where to start looking for the root cause and possible solutions, or have an theories on those points?