Engine, disassembling and assembling
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Before beginning repairs on the electrical system:
Obtain the anti-theft radio security code.
Switch the ignition off.
Disconnect the battery Ground (GND) strap.
On vehicles equipped with Audi Telematics by OnStar, switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting vehicle battery โ 91 - COMMUNICATION
After reconnecting vehicle battery, re-code and check operation of anti-theft radio. Also check operation of clock and power windows according to Repair Article and/or Owners Manual.
After reconnecting vehicle battery on vehicles equipped with Audi Telematics by OnStar, switch-on the emergency (back-up) battery for the Telematic/Telephone Control Module โ 91 - COMMUNICATION