warning lights issue and more. pls. help!

Hi all,

a while ago I got my 2001 BMW 525ia's seat belt light went on, and stay on after start...then days later the air bag light goes on and stay on after start.

then a few days later, the seat belt light never light on, just the air bag light stays on... then days later the lit air bag light becomes dimmed and eventually stoped light on.

at this point, the seat belt and air bag lights won't lit in any circumstance, including when ignition key is in pre-start position.

the steering wheel function keys are not working except for the heater, when button pressed, it will lit up and heat up. after a while the green LED dot also becomes dimmed and almost non-noticeable if it is on or off, however the heater still works.

radio display sometimes flashing, and the clock display won't show up when not listening on audio ( I think it supposed to display time when audio not turned on) but when in normal driving, the radio display seems working better.

seat heater lights are not on, but I didn't test it long to see if actually it produce heat like the steering wheel heater does.

vanity mirror will make the central light goes on.

since those are trivial, and I thought it just some electronical connection issue, maybe the fuse, so I didn't do anything. after checking the fuses are fine. I knew it is more complicated than I hoped.

then a few days ago, the fail-safe tranny light went on, shutting the car off, then try again, it will go on eventually if not immediately.

shortly before that, I can feel the transmission was trying to shift down when I was driving normally (feels like someone is pulling you from behind when you are running).

now I am more worried.

brought it to a servce garage, have it scanned by the autologic computer, has 19 errors. reset them (to see how it works). at the same time the mechanic found my brake light is always on. tried a new brake switch but it didn't solve the issue, the mechanic tried to reprogrammed the lamp module, first time didn't work, 2nd time it worked, so then the fail-safe tranny light goes off. the mechanic ask me to see if the warning light will go on again, if so, I need to bring it back.

I drove it on local, feels good, goes on a highway, when I accelerate to 120KM/Hr, the fail-safe tranny light goes on again. but when I shut the car off and on again, the tranny light is not lighting up (so far after 5 times started the car in the past two days)

that is all up to now. the car now still runs well except the seat belt light and air bag lights always stay off and no function keys on steering wheel works (except for the heater). But I do want to clear things up and got them fixed before it causing more confusion... my car only have 92000KM on it, so I wouldn't think any mechanic issue with the transmission?

Can someone tell me if I shall check the ignition switch as well? and if so how? and how to clean it? the ignition switch is not very expensive, isn't it? or it is actually costly.

thanks for helping!

Search for "Ignition Switch", $70 item easy DIY.

the under charged battery was proved to be the culprit!

charged mine from 70% to 100%, everything went normal.

thanks everyone.

Sounds like a similar problem to mine w a 540.. I am Gonna go home and charge my battery ASAP!
Thanks!

Ditto cn90