Hello All, newbie here. I have gotten some good advice off the forum here and wanted to share this.
Here is my story on the Trans fail safe light. You might not believe me..but true...at least so far. Knock on wood!
I had the trans fail safe light come on sporadically over the past 12 months. Sometimes the Brake warning light and yellow triangle looking light also. Always reset after stopping and restarting. Well it seemed to get worse after a very long trip to Texas. One day I got a check brake light bulb (bulb out). Indeed upon checking, the right brake light wasn't working. I pulled out the bulb, but it looked fine. Went to ORielly's to get a new bulb. I decided to look it up in the book first. GLAD I DID! The bulb listed (can't remember #) was not what I had in my hand! Hum... I bought the bulb listed and installed. Check Light went out, brake light works...AND I have not had the trans fail safe, brake warning light issue since!
Note: when I pulled the incorrect bulb out- it was so hot I couldn't hold it with my bare hand! The brakes were not applied for an extended period either. I bought X5 used and the wrong bulb must of been installed by them or their mechanic.
I'm guessing that the wrong bulb was causing a voltage or resistance issue somewhere (DSC ?) and that was causing the problem. BTW, my brake bulb circuit board seems to be fine. Wish I kept the wrong bulb to tell you wrong one installed. More important is to make sure correct number is installed.
I hope I didn't jinx myself but after about two months and several 4 hour drives in the Texas heat- no issues. Based on the last 12 months..I would definitely encountered the issue again by now.
Check all of your brake lights for the proper bulb! Doesn't take 5 min and it might just save you big $$. That's my story and wanted to share. My fingers are still crossed


2003 X5 3.0 GM Auto Trans 110,000 miles