What (sensor?) controls warning notification of things

[zen2u]

First off props to all the gurus out there sharing all their knowledge! Huge resource and a big thx!

2005 X5 4.8is, 72k, So Cal weather only, bought in 07 with 12k miles :

Wondering if there is some electronic sensor or other widget needing replaced due to this:

Now and then (1-2'ish times a month), while driving, the following things happen SIMULTANEOUSLY

1) I get an audible tone (like the seat belt tone) but only 1 audible "bong"
2) Various cluster lights come on. 4x4 light, trans, and others.
3) Power steering seems to get funny.
4) Trans never shifts and the rpm's are high (like 4-5 thou at 50-55 mph if on the highway and I hobble to the next exit going as slow as possible with the tac screaming).

There never seems to be the exact warnings lights each time but hard to tell since when it happens I'm focusing of getting to a safe lane or exit vs. memorizing the cluster. But man, the dash cluster becomes christmas tree lights, bam everywhere lights.

* So I pull over (or red light) turn off engine then turn back on and 90% of the time it all clears. By clear i mean the car now shift and drives fine and I keep driving. The remaining times I've shut it down and later when starting it is gone until its next episode.

I cannot image that so many things go bad at once thus it must be a sensor or something vs. each item's warning indicator meaning multiple failures are happening at once. What are the odds of that?

I am at whits end. Someone just club me at this point. Anyone out there familiar with this first hand or not? My luck with the BMW dealers is such that nothing is worth sharing on that front.

[Quicksilver]

The 1 audible "bong" could be low outside temperature warning which bongs at 37 degrees. The other Bong could be the clock alarm going off. (Took me a while to find that one.)
Sometime you can get a signal if theres a system fault which will show up in the OBC window.

[gerry_miranda]

Sounds like an alternator going bad...

[JCL]

The warnings are connected to various modules (TCU for transmission, DSC for ABS/4x4, DME for the engine speed)

A common reason for false warnings is low battery voltage. Is it the original battery? If so, I would check it first.

[zen2u]

Thanks you guys. Here in San Diego we dont get the 37 temp or less but good to know if I ever move back east.

A certified repair place put a new (BMW recommended) battery in last year. I will look into the alternator too!

Oddly, while driving just after posting my thread/question, I was reminded of another quirk when the radio sound turned off for several seconds (but orange power light remained on) then powered back up. This was another thing that I forgot to add earlier.

Maybe further supports the alternator theory. Thx!

[killcrap]

sounds like an alternator, interrogating the fault memory to check for overvoltage faults.

[ArmyX5]

Originally Posted by zen2u

Thanks you guys. Here in San Diego we dont get the 37 temp or less but good to know if I ever move back east.

A certified repair place put a new (BMW recommended) battery in last year. I will look into the alternator too!

Oddly, while driving just after posting my thread/question, I was reminded of another quirk when the radio sound turned off for several seconds (but orange power light remained on) then powered back up. This was another thing that I forgot to add earlier.

Maybe further supports the alternator theory. Thx!

Zen2u, I have been having the same issue with the radio sound turning off for a few seconds also. It always happen when I am taking off from a dead stop. I have not been able to find out the cause of this problem yet

[Nik]

Check voltages. easy to do.

[knoxroks]

I'm having the symptoms , what turned out to be the problem?