Just bought an X5 4.4i 03 for my wife about 2 months ago. service indicator light comes on after the engine start but it turns off. The manual is not clear. I see a row of green dashes followed by a yellow LED. But the indicator does not stay on. My 00 328i has a mileage counter that makes it easy to know when the next service is due. I checked with the dealer and they tell me last service was done Nov. 06.
How do you interpert the service indicator light.

If more than one green LED is lit, you're ok. If you're down to 1 green LED, it's almost time to service it. When there is a yellow LED, it's due. The display will tell you if it's an oil service or an inspection. When it's yellow and red, its overdue. When it's yellow and red and both oil service and inspection are lit, you need to take better care of your car. :stickoutt

but does anyone know how are the green and yellow led's triggered? by a certain amount of time? amount of miles? are there sensors somewhere?

Fuel consumption.

you can reset the lights using the cluster itself

Fuel consumption.

can you be more specific?

bmw calls "fuel consumption" a TI signal which comes from injector frequency

you know the green led's on the cluster under the oil service text, each green l.e.d. has a specific value..hope that helped a little ...