Under the hood on the passenger side (Left hand Drive) at the base of the windshield, there is a box. In the box there is the engine computer (ECU) and the transmission controller.

One dark, wet, rainy night traveling home on I-83 in York, PA my trans went into fail safe mode.

Long story short. . .I found water in that box. Used a hair dryer to gently dry the electronics and RTV to seal it. And all lived happily ever after.

If they find a bunch of goofy codes that have them stumped, look for traces of water in the box.

FWIW, I have the same problem BUT ONLY WHEN IT IS HOT. If the temperature is below 80 degrees, I don't get the lights, or if the car is cold, and it's hot out, I won't get the lights until I drive around for a while.

After a lot of reading, it APPEARS to be a bad ABS module.

But I wanted to know if everyone else was only having the problem when hot....

I was just looking for info on this same problem. I have had all the lights on for almost a year. I just had a new tranny put in and new brakes on my 2001 X5 4.4 (82k miles). They replaced one brake sensor that looked bad, but the lights are still on. This was not an authorized BMW dealer, so I guess I should take it in to get the fault codes.

The new tranny has an issue that I think is computer related (company who put in new tranny doesn't feel it is their problem) and sounds like it could be in corrrelation to these abs lights coming on. When I step on the gas hard, the transfail safe lights come on and it feels like I am driving in 5th gear. When that happens, I can't use the steptronic. If I don't step on it too hard, all shifting works fine and steptronic works fine.

Is it possible that with the ABS and DSC lights on, it is affecting the transmission as well? I am hoping maybe it is another brake sensor that needs to be replaced and all will be fixed.

Just have someone who has DIS or code reader to diagonse the fault code, it saves lot of money.

Hi, Roger has good idea, allways have proper diagnostics check. I purchased X5 with 43k so i do not know car history.I do know that some one replaced left front cv boot because that wheel and all surrounding components were covered with grease.When doing that repair,the wheel bearing is removed and it has impulse wheel attached,which could have been damaged. Even though diagnostics said sensor fault i still worry that impulse wheel could be faulty. Another possible cause is brake pad wear sensor as the one fitted to car was not correct length and it stretched baring wires which may have put power spike through hub thus sensor, causing fault code.Dealer replaced pad wear cable at first fault code. The second time i got malfunction, the pads were nearly worn so the power spike could have been pad sensor but i doubt if pad wear sensor causes such problems unless speed sensor also defective. So new pads to all wheels,new pad sensors front and rear, new speed sensor left front and hope for the best. So all you people with similar problems may want to have correct diagnostics check done and take it from there what could be done to fix.Wish you all good luck.

Hi, Roger has good idea, allways have proper diagnostics check. I purchased X5 with 43k so i do not know car history.I do know that some one replaced left front cv boot because that wheel and all surrounding components were covered with grease.When doing that repair,the wheel bearing is removed and it has impulse wheel attached,which could have been damaged. Even though diagnostics said sensor fault i still worry that impulse wheel could be faulty. Another possible cause is brake pad wear sensor as the one fitted to car was not correct length and it stretched baring wires which may have put power spike through hub thus sensor, causing fault code.Dealer replaced pad wear cable at first fault code. The second time i got malfunction, the pads were nearly worn so the power spike could have been pad sensor but i doubt if pad wear sensor causes such problems unless speed sensor also defective. So new pads to all wheels,new pad sensors front and rear, new speed sensor left front and hope for the best. So all you people with similar problems may want to have correct diagnostics check done and take it from there what could be done to fix.Wish you all good luck.

Hi, A new problem
 

Hi, I remplaced the abs sensor, the dcs unit and all the lights come off, but there are a new problem, the speedo don`t work, my mechanical say that is proble the instruments cluster, what do you think?

Brake switch cheap fix
 

I too had an odd occurrance of "trans failsafe prog" right after I tried to turn cruise on. Immediately I got a quick lull in engine (or brake apply, uncertain as it was momentary), then got DSC Inactive, then brake light on, Service Engine Soon on, and finally the dreaded "trans failsafe prog". Knowing about this in previous work I didn't pull over as I was on a road trip between cities and didn't want to get stuck in 2nd gear only. Trans worked perfectly fine but I suspected I wasn't into "lockup" only costing about 200 rpm in fuel. Took it to local trusted mechanic (not stealer) next day and $135 later and a new brake switch and she's as good as new....at least for 128k. Dealer suggested I replace the Trans ECU BTW. Hope this helps. Never underestimate your gut!!!

amacman, if the brakes applied themselves when this problem happened, it is likely that they saw that wheel as traveling faster or slower than it actually was (compared to the other wheels) due to the malfunctioning sensor... causing the dsc to activate the abs to that wheel to stop the "spinning out" it thought it saw, attempting to keep the vehicle in control for you... under false information from its sensors.

I cannot believe how ignorant some owners of cars be. "one more chance to fix problem".......

It is so simple and you understand precisely how the system works and what the diagnosis entails. After the remaining chance are you going to blow your fuse or bag the dealer on the net?
Either way no doubt you will do it in ignorance