Q: iPhone. 6 phone book problem

Hi, Pan67.  

Thank you for visiting Apple Support Communities. 

I understand your iPhone no longer syncs the address book with your system.  Sometimes pairing the device with your vehicle again can solve this issue.  You may need to reference your vehicle user guide for the pairing instructions and code. 

iOS: Third-party Bluetooth accessories

http://support.apple.com/kb/ht1664

If the issue persists, here are some additional troubleshooting steps that may help.  You may also have to reach out to the vehicle manufacture for firmware updates to the vehicle.  

Get help using your iPhone, iPad, or iPod touch with your car stereo

http://support.apple.com/en-us/HT203412

Cheers,

Jason H.