Had the TRANS FAIL SAFE light come on in my 2005 X5 with 105,000 miles on the odometer and thought I would share the outcome.

Here's what the service writer wrote on the work order:
Customer request check electrical system: seat heaters inop "TRANS FAIL SAFE" message on "Brake" light on. Airbag light, fasten seat belt chime sounding with no one in seat. Only 1 day headlights were flashing.
Ignition switch permanent malfunction
Checked battery. Okay. Checked starting and charging system. Okay. Performed short test. Several control units not identified. Checked fuses. Several fuses are without power. Checked power supply for affected fuses. Powered by ignition switch. Replaced ignition switch. Cleared faults, check ok.

Part number: 61-32-6-901-962 ignition switch: $91.94

BMW service coupon: -25.00

Labor: 250.00

BMW shop supplies/ hazard wast: 25.00

Tax: 9.61

Total: 351.55

Problem started on Tuesday. I immediately started researching the XOutpost forum and found lots of TRANS FAIL SAFE posts but nothing that matched the problems my SAV was having. I tried to find the cause of the problems throughout the week and realized I couldn't self diagnosis. So, I called my local BMW dealer on Saturday morning at 10:30am they said to bring in the vehicle and they would look at it. Diagnosed and repaired same day while I waited. Out by 1:10pm with a free car wash and some BMW wheel cleaner. Had a great experience with the BMW dealer. I will continue to perform as much of the maintenance on the vehicle myself using this forum for reference but I also know when it's time for help. It's nice to have a positive relationship with my local dealer.