Google modified the handling of the Bluetooth "Service Discovery" database (again) and now some cars can no longer be paired with phones using LineageOS 14. Strange enough everything is fine with the original Android 7, e.g. with a Nexus 5X. See here for a list of affected cars.
I'll try to add another hack to the Bluetooth driver to fix this problem, but it may take some time.
One user notified me that he managed to pair his Mercedes SAP V2 adapter with his phone by initiating the pairing from the phone. He touched the "MB-Bluetooth" device in Android Bluetooth settings, while the adapter was (unsuccessfully) searching for the phone. Maybe it works for others as well.
It looks like the rSAP app is used in more configurations than I can imagine. I tried to run the new version on as many phones with a lot of Android versions and different SOCs, but it is still not working for some users. So I decided to publish two more updates to the app (trial and full version):
I'm sorry for all the troubles which the update caused. I hope this will not happen again...
Today I released version 3.0 of the rSAP app. It is a complete redesign of the app, it is now prepared for the coming Android Nougat. I already ran it successfully on a Nexus 5X with the Nougat pre-release. Big changes were made in the user interface. I removed all outdated options and tried to better show error conditions. I also removed the SIM check, I will add this again when I find the time.
In case you find problems please report them in the forum.
Sadly some other issues showed up which I could not yet fix:
I'm working on both problems but cannot say so far when (or if) I have a solution.
Today I published a new version of the installer app (2.5.9). It supports additional newer or 64 bit phones. On these phones a special "factory test mode" must be set to create the necessary file in the baseband's file system. Additionally the phone must be rebooted after setting the test mode.
Some phones don't remember the test mode after the reboot, so you still cannot make the change to the baseband settings. The Oneplus Two is affected by this problem. I'll keep trying to find a solution for these phones.
I received my Nexus 5X and I finally could check what happens on a 64 bit Qualcomm phone when you don't get ACCESS DENIED: the system files crash :-(
Version 2.5.7 of the installer app fixes this crash and works nicely on a Nexus 5X, in contrast to the Google stock rSAP implementation.
Fun fact: the Nexus 5X does not have sap_security_restrictions set in the baseband's NV storage, but it still works...? I guess there is some more research necessary for the 64 bit Qualcomms.