Cadillac cts

First thing is to check all the fuses, those under the hood and the interior ones as well, if those check good then I suspect that there is water damage done to the vehicles BCM. Have you check the communication or OBD2 port to see if the computers are transferring data?

Where are the fuses located inside the car? I am a mechanic of 32 yrs. But certain vehicles still stump me.

Gotcha beat retired with 35 years, anyway they are under the rear seat cushion, take it out and you will have one on the drivers side and the passenger side. Good Luck.

Ok, I just want to thank you for all your help, I found the other two fuse boxes under the rear seat. Found a 10amp fuse blown, replaced it, got power to everything and started my car. I only have 1 more question? My radio is in German language, how can I change that?

Hopefully you can pull up the menu on the main screen and change the language to English. My Caddie has a menu button but there is no selection for language but it is a little older than yours. If there is an owners manual there might be more information in that. Even an old car mechanic can learn something in an owners manual, I know my Yukon manual taught me a few things.

Ok, i was able to start car yesterday after replacing a fuse and no engine codes showed up, now today car will not start unless I put a jumper wire on purple wire in fuse box and run it to the got post with key on, and now I have engine code UO100. Googled it and I have lost communication with ECM. Where is ecm located on my car please

Two places depending on what engine you have, one has the unit on the right side front of the engine, the V8 version has one underneath, you have to remove the large splash shield in front to gain access to it.