Functional testing

WARNING: This page is about a different car, the 2004 Audi A6, 2003 Audi A6, 2002 Audi A6, 2001 Audi A6, and 2000 Audi A6. However, it is still accessible from the selected car via links, so may be relevant.

Switch ignition on.
The MIL must light up.

If the MIL does not light:

Check DTC memory. See DIAGNOSTIC TROUBLE CODE (DTC) MEMORY, CHECKING AND ERASING .