General information: Notes
CAUTION:
Before beginning repairs on the electrical system:
- Obtain the anti-theft radio security code.
- Switch off all electrical consumers.
- Switch ignition off and remove ignition key.
- Disconnect negative (-) battery terminal.
- 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. See EMERGENCY (BACK-UP) BATTERY, SWITCH ON/OFF, RESET TIME REGISTER .
- After reconnecting vehicle battery, re-code and check operation of anti-theft radio. Also check operation of clock and power windows according to Repair Manual and/or Owner's Manual.
- After reconnecting vehicle battery on vehicles equipped with Audi Telematics by OnStar(R), switch-on the emergency (back-up) battery for the Telematic/Telephone Control Module. See EMERGENCY (BACK-UP) BATTERY, SWITCH ON/OFF, RESET TIME REGISTER .
All A6 from m.y. 2001 are equipped with Immobilizer Generation III.
Generation III has the same functionality as the previous version. However, in addition to the normal data exchange between the immobilizer control module and ignition key, Gen. III includes data exchange between the immobilizer control module and Engine Control Module (ECM).
Data exchange between the Immobilizer control module and ECM takes place over the vehicle CAN-Bus network.
NOTE:
- For Immobilizer III, the Engine Control Module (ECM) is actively incorporated into the evaluation and monitoring. The control module for immobilizer is integrated into the instrument cluster, i.e. the control module for immobilizer is replaced together with the instrument cluster. See INSTRUMENT CLUSTER, REMOVING AND INSTALLING .
- For immobilizer III, the keys are marked with an inscribed "W". The code consists of a fixed code and a variable code portion.