MIL functional check

WARNING: This page is about a different car, the 1999 Audi A8, 1998 Audi A8, and 1997 Audi A8. 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 lights up when the ignition is switched on (with the engine not running):

Check DTC memory. See ON BOARD DIAGNOSTIC (OBD II), CONDUCTING PROGRAM .
If necessary, check wiring per wiring diagram or replace light bulb.
Start engine and let idle.
The MIL must be switched off after several seconds.

If the MIL is not switched off after the engine is started:

Check DTC memory. See ON BOARD DIAGNOSTIC (OBD II), CONDUCTING PROGRAM .