mm9351

I have a 2020 GLE450 (less than 15K miles) with virtually no issues up until a few weeks ago. First, the MBUX head unit went unresponsive for a few minutes while driving. Then it restored, by itself, and everything operated normally for several weeks. Lately i noticed that memory setting don't save overnight, e.g. passenger mirror setting and steering wheel doesn't restore to driving condition. Last night, I noticed that all ambient strip lighting on the dash, center console grab handles, cup holders, and doors stopped illuminating. Only ambient strip lights that work is on driver's door. These driver door lights still do the red / blue color change to climate control settings. I do notice that the driver's footwell lamps ":flashes" every few moments, especially if I activate something i.e. heated cup holders. I will be checking some fuses later today, but I suspect a wire harness issue. Settings for ambient lighting on MBUX still working fine, as it appears the ambient lighting controller is OK (can still change the lighting color on the driver's door). Anyone experience this? Please let me know how you got this resolved. I anticipate a trip to dealer service will be needed. :Luckily still under factory warranty, but suspect that wiring harness issues are difficult to diagnose, and even worse, impossible to access. Appreciate your inputs on this subject. Thanks in advance.

Neurobit

With electrical issues it could be a number of things. Perhaps the connector feeding the LED strip, or could be it just plain died, which is rare (I don’t recall ever seeing this posted here).
Have you checked for blown fuses? Should be easy for dealer to fix since it’s not intermittent (those issues are the hardest to pinpoint).

Cheers,

Lucky 777

Disconnect the negative terminal of the battery under the drivers seat for a few minutes and then reconnect... see if that clears everything up.

Sieveboy

had the same thing, only the driver's door was on. I took it in and they "updated the software", but who knows what they really did.

mm9351

Many thanks for your responses. Since I rarely have luck trying to resolve electrical issues on MBs, I called the service department only to find out they would need several hours to evaluate the issue. OK I thought, I could deal with a loaner. Here's where it goes downhill quickly, the service loaner is not available until November 21, which is over six weeks from today. So the next step, obviously, is to check out the fuse situation. As many of you know, there are (3) fuse panels; under hood; passenger footwell, and trunk passenger side. A quick review of the fuse locator sheet points to F317 which is a 7.5 amp brown fuse well hidden in the trunk panel. You need to remove the piggy back fuse holder to access it. I pulled the fuse, and of course it was fine. After a few moments I re-installed the same fuse, go back in the car and.....would you believe....the ambient lighting is fully restored! So much for a 'software update.' I would imagine a negative battery terminal pull would have also worked. I hope my experience can help others should you have this condition, without requiring a trip to the service department.

Frenetic

I feel your pain. That’s why I’m hesitant to take my car in for a serious safety issue without trying to solve this myself. No loaners with a backup a mile long. These dealers must be milking MBUSA dry with all of the warranty work, even if MB caps the repair costs.

What I’m worried about is that my issue is intermittent and I know these dealers like the back of my hand. They will not try to reproduce the issue unless it freaking slaps them across their faces. I need to figure this out. I don’t want repeat visits but my issue is a good avenue towards lemoning this thing if I wanted.

Neurobit

Easy fix! Glad to hear you got it resolved!

haibieb

Last night, we had to re-set our ambient lighting system. Don't ask me what caused it to re-set to all white. But, it is now working. The level and complexity of electronics in our vehicles in general, is truly overwhelming.

charlesroy

Thanks for the post, I am trying to get the piggyback fuse cover off the rear fuse panel, I don’t want to break anything. How did you get that thing off the fuse panel ? Thanks.

mm9351

By using a small flat blade screw driver and lots of patience. If you examine the mounting there are 2 or 3 tabs that need to be pressed while exerting lifting force from the main assembly. Work slowly and carefully until the block lifts from the base.

Virginbenz

hi - can you confirm the fuse is actually 417 instead of 317? 417 i believe according to the fuse sheet, refers to Ambient lighting which is what we should be looking at, is that right?