david412

I have a 2015 E Class coupe in the UK, Recently, in hot weather I started the car and a distance recognition failure message, check handbook, appeared. The actual warning message is irrelevant here, because I could not clear the message as all steering wheel function was not working. Worse still, the electronic gear selection was not working either. I had to use another car!. Returning to the car later when the temperature cooled, the car ran as normal, all functions working. This reoccurred the following day with the same outcome. Now the car is back to normal (there were endless malfunction messages which we cleared down). Has anyone else experience this and what is the solution? Thanks.

Mr. Toad

It's hard to imagine such a problem being temperature-dependent, because I live in Florida, US, and I know there's nowhere in the UK that's hotter than it consistently is here!

pl626

How fresh is the Aux battery?

david412

Less than a year old.

StuttgartHorses

what mileage is it and model? Somewhat irrelevant but definitely a strange problem. Both of my batteries going low over time didnt do that. I saw the symptoms of both. Although a presage inoperable light came on and made my blind spots now work along with plenty other things like brake hood eco mode hill braking assist. Then was all cleared once aux battery replaced. This could be some main battery voltage problem. But I don’t know other than that. Maybe software, requiring one of the future updates. Strange.
my coupes from LA and then texas it’s other half of its life. So its from very hot places.

Edit: the parking brakes are the unreliable part of these cars generally. That being broken is an easy fix i fixed mine in one minute with bare hands once it wouldnt engage. And the release handle was stuck out.
Also the early versions of this 7 spd did have trouble reaching reverse at points. But it was a TCU issue. Your TCU may somehow be acting up big time. Lemon TCU possibly :/