gear box

hello
i have a bmw 320i model 1992
recentley the gear box light turned on, and the car stayed on the 3rd gear and didnt shift anymore, i turn it off and on again , still the same problem,
i parked the car on a kind of a small hill were the front of the car is a bit up
and turn it off and back on again , the light disappeard,
i have recentlty changed the gear box oil and the filter and the gear box operates normaly when the light is of
some garage says thats i should change the gear box sensor, some other says that it might be something else
please advise me
thank you very much

This could be anything, but one way to find out is to have diagnostic done on the car if it can be done.

Not sure if it is achievable on a earlier version of the BMW.

Good luck

Check fluid levels.

well
after plugging the scanner
the error was " selector lever"
sp we changed the yellow rubber under the geard box selector lever