Hello,

I have a 2017 300S. Had an issue where there was enough voltage to power the vehicle, but it would not start the engine. I went ahead and replaced the battery (dated 2019), and now the uConnect system will not turn on (radio, camera, etc), and the display notifies me that the blind spot markers are temporarily disabled (just stay lit up within the side mirrors). The check engine light was on, but it's gone away. I've started and driven it a bit now, thinking the computer would be reset, and it might clear itself up, but it hasn't. I have an OBD II pocket scan; I thought I would plug it in and see if anything was left over from the minimal voltage before replacing the battery. I was also going to check fuses.

Thanks for the guidance!

 

Update - disconnecting the negative terminal on this newly installed battery has allowed for the uConnect system to power on, and for the blind spot markers to become "enabled". Now, have to resolve the matter of no volume coming out of the system (radio, Bluetooth device), and hopefully will be back to 100%.

 

It could be you did not get a complete reset on your system. Disconnect the Neg terminal (like before) but this time hold it to the Pos terminal for 10 seconds. Be double damn sure it's the Neg terminal you are disconnecting. Okay ?

Do report back to us.

 

Yes, that's what did the trick (disconnecting the neg). Interesting because the backup camera and radio volume were the last bits to properly "come back" but everything is working as it should be.

 

All's well that ends well. Many thanks for getting back to us.