Battery Disconnect Precautions
WARNING: This page is about a different car, the 2002 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
When battery or ECM is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until adaptation systems have completed a relearn cycle. See 2002 COMPUTER RELEARN PROCEDURES or 2003 COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.
Before disconnecting battery, obtain anti-theft code for radio. After reconnecting battery, re-code and check operation of anti-theft radio. Also check operation of clock and power windows. On vehicles equipped with Audi Telematics by OnStar(R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting vehicle battery. Emergency battery is turned on and off using VAG 1551/VAG 1552 or VAS 5051/VAS 5052 scan tool in address word 75 - TELEMATICS set to function 10 - ADAPTATION CHANNEL 08.