For reset the OIL message that appears in your Audi A4 B5 dash panel odometer screen, follow the instructions:

 For 1994 to 1999 cars:

Step 1. Insert your key into the ignition (do not turn it)
Step 2. Push in the odometer reset button (right button), hold it pressed, and turn the key to the first click.
Step 3. In the display, “oil” or “service” or “insp” should now be shown. If it does not, repeat steps 1. and 2.
Step 4. To reset, pull out your instrument light dimmer button at the bottom of the tachometer. (—— are now displayed)
Step 5. Turn the ignition to the off position. When the ignition is turned back on, the display should be back to the trip odometer.

For 2000 to 2001 cars:

Step 1. Insert your key into the ignition (do not turn it)
Step 2. Push in the odometer reset button (right button), hold it pressed, and turn the key to the first click.
Step 3. In the display, “oil” or “service” or “insp” should now be shown. If it does not, repeat steps 1. and 2.
Step 4. To reset, push the clock adjustment knob the bottom of the tachometer.(—— are now displayed)
Step 5. Turn the ignition to the off position. When the ignition is turned back on, the display should be back to the trip odometer.

The instructions in this tutorial will work in the following model years:

1994, 1995, 1996, 1997, 1998, 1999, 2000 and 2001 Audi A4 B5 Petrol (1.6, 1.8, 1.8T, 2.4 v6, 2.8 v6) and Diesel (1.9 TDI and 2.5 TDI) Engines, S4 and RS4