Got it from a website.Forgot which one but it works.Plagiarism not intended.
Instrument Cluster SIA Reset
For model: E38, E39, E46, E52 and E53
Production date: E46 from 9/99 and E38, E39, E53 from 9/00
On 2001 vehicles without the diagnostic port in the engine compartment, the use of the SIA reset tools in not possible. The service indicator may be reset using the reset mode in the instrument cluster.
• Ignition key must be off
• Press and hold the trip odometer reset button in the instrument cluster (left button), and turn the ignition key to the first position.
• Keep the button pressed for approx. 5 seconds until one of the following words appear in the display: "Oil Service" or "Inspection", with "Reset".
The service due is shown with "reset" if the coded minimum consumption limit has been reached and resetting is possible. If "reset" is not shown, the minimum limit has not been reached and resetting is not possible.
• Press and hold the reset button again until the word "Reset" begins to flash.
• While the display is flashing, press the left button briefly to reset the service interval. After the display has shown the new interval the following will appear: "End SIA".
The system can only be reset again after 2.5 gal (10 liters) of fuel have been consumed.
E46 service interval reset
Keep Button pressed for 5 seconds after key is switched on. Tap button of reset display.
Reset procedure for clusters with SIA IV using the reset mode (possible form 9/99 for E46, MY2001 E52).
• Ignition key must be off.
• Press and hold the trip odometer button in the instrument cluster (left button) and turn the ignition key to the first position.
• Keep the button pressed for approx. 5 seconds until one of the following words appear in the display: "Oil Change" or "Inspection" with "Reset".
• Release the reset button and press and hold again the "Reset " begins to flash.
• While the display is flashing, press the left button briefly to reset the service interval. After the display has shown the new interval, the following will appear: "End SIA".
The system can only be reset again after 2.5 gal (10 liters) of fuel have been consumed