Supersedes Technical Service Bulletin Group 00 number 14-58 dated January 31, 2014. If a 2012 - 2016 Audi A8 L W12 arrives at an Audi dealership and requires diagnosis or repair, a Repair Authorization must be obtained. Prior to any repair, a Technical Assistance Center (TAC) ticket must be created for engine and transmission concerns only. Routine maintenance and PDI do not require prior authorization or a Technical Assistance Center (TAC) ticket. These procedures are mandatory until further notice.