mihir_d

My 00 320 - 88K miles...

first time this has ever happened in 6 years..while driving, the MCS suddenly died on me, and the display just swinged open...will not close no matter what...all MCS functions died, Radio, CD, Navigation etc. etc. it almost seemed like some firmware bug brought it down...so I pulled over, shut down the ignition and re-started the truck after 2-3 minutes...in the hope that a complete reboot of the MCS will fix the problem, but that didn't work...

I was on a 200 mile drive, and so had to continue that way with the MCS screen flipped open all the way till the end of the trip...all the time taking extra caution not to damage the screen my accidently bumping my/co-passenger's hands in it...

Once back home, the last thing, I wanted to discover was that the MCS had just died and would need a complete replacement (I have heard that horror story on this forum before)....

Common sense told me that the simplest cause could be a blown fuse in the fuse box..so I opened the fuse box and located the Radio/MCS fuse (F21)...apparently found nothing wrong with it....again common sense hinted to me that although not blown, it might have become lose with some of the bumpy ride that the truck gets off and on (only on road bumpiness..no off roading)...so decided to just pluck it out and re-insert it firmly...volla!!! the MCS sprung back to life..

All functions returned to normal....I was obviously delighted to see it come back, but felt that this shouldn't have happened in the first place..

Don't auto manufacturers test the fuse box and fuse design to withstand normal automotive vibrations...this one especially shouldn't do this since it is an SUV tested for off road bumps too...and mine seemed to have become lose just by on road use...

Any comments???

55fanatic

I cant comment on mercedes' testing but over time those fuses wear out on the edges... Ive also seen in various cars the contacts over time lose some rigidity, all you can do is bend them in a way to increase tension again or get an unworn fuse...

For your particular case was any service done on the vehicle recently? Were any other Fuses changed lately? maybe someone just loosened it by accident and didnt realize it?

mihir_d

The last A service, I chose to perform myself...its mostly just an oil change, so I didn't take it in to the dealer.

It will be going to the dealer for the B service, sometime this summer.

Thus, the fuse box has been practically untouched for a while...the only work ever done in my fuse box was the auxillary fan wiring harness upgrade/fuse upgrade under warranty at 45K miles...(almost 3 years back)

I guess, then, it wouldn't hurt to re-tighten the fuses by merely pressing each one in its socket, just as preventive maintenance...

This post should serve as a good hint to anyone who experiences a similar abrupt abnormal behavior....check the fuse box first before considering anything....

azinn

Been there, done that. This has happened to me several times over the last six years of ownership. Don't know what the cause is, but pulling the fuse and reinstalling it always works.