I just wanted to give a quick updates on anyone experiencing any issues with SYNC such as connectivity and it being just to slow and noticed a vast improvement after downsizing my contacts and deleting all my(text) messages on sync,hope this helps someone. Z BCM 5865 – 2011 – 2013 Vehicles – MyTouch Functional Issues Due To Phonebook Content – Contact Volume
Some MyTouch equipped vehicles may experience multiple functional issues such as slow navigation calculations,
displayed time jump or audio popping during initial ignition on cycle. These conditions can be created by the size
of the contact list within the customer's phone book. The amount of data within the contact list can create a
processing problem for the mobile during a key on cycle. This can be resolved by limiting the number and/or
content within the contact list. In addition, the automatic phonebook download feature can be set to off by
selecting phone, settings, manage phone book, turn auto phone book off. Additional phone contacts can be added
by manually re-downloading phone book in that same menu. Recommend following Workshop Manual section
415-00 for additional diagnostics and ensure a master reset is performed.