Trans Failsafe display comes up every day when im driving. Radio cuts out as soon as this display is triggered. Also had cel light come after and traction control light, code was secondary solonoid electrical. When you restart car everything is fine. First time this happened wife left headlights on and killed the battery, that was months ago and the battery is new and fully charged. Searching and found answers of ignition switch, or battery/alternator. What you guys think its a electrical issue or some transmission module, Where to start to check. Car is a 2000 740IL, 195000kms runs fine when all displays are off, no Cel issues

Radio cutting out is a very common symptoms of ignitions switch. If strange things occur when you open the passenger sun visor mirror, then it's the ignition switch. Otherwise, as your searches have indicated, I would have your battery and alternator tested.

Radio cutting out is a very common symptoms of ignitions switch. If strange things occur when you open the passenger sun visor mirror, then it's the ignition switch. Otherwise, as your searches have indicated, I would have your battery and alternator tested.

+1

Thanks I am going to have the alternator tested as the battery is new. Will check that sunvisor next time this happens.

I also have tran fail safe problems. I can't quite pin when it happens but it seems random, about 70% of my starts!

i had the same problem and it was my battery. Once i got it replaced, everything was fine. since u said u replaced urs recently and is new, then i dont know what it is

I got a brand new battery and the problem still exists.
The car has light damage to the trunk and bumper after being hit by a toy truck, could this have scrambled something?

It was the alternator going bad, voltage was only about 11.5 output. When i fully charged the battery all was good but as the voltage dipped I would have the same problem. Had alternator replaced plus tensioner and belts and all is well.

my alternator is cranking out healthy voltages. Im gonna try and get a new ignition switch sometime soon.

While we are on ignition switches- My friend was having starting/running/radio problems in his F body Z28, replaced it and everything turned out fine. The old one was deep fried on the circuits.