2000 ML320 Dead Radio

[tgrand]

Hi Everybody,

I just got this SUV a couple days ago and when I got in this morning the radio didn't come on. I had it on last night while wipping it down after washing and then noticed this morning that I didn't completely shut the drivers door. Anyway I start up and the radio is completely dead. No display, reset request nothing. The nearest dealer is an hour away and only open for service during the week. I'm not real thrilled about taking off a day to get the radio reset or whatever. Has anyone had this experience?

Your help is always appreciated.

[Lebenz]

Sorry to relay to you that I had the MCS in mine replaced 4 times. That sucked. First one was due to the cassette ejecting every time it played the 2nd side of the tape (in other words, a bad tape drive motor). Second one lasted less than 1 day. It had the same problem as yours. Third one worked great except it wouldn’t play above about ˝ volume. 4th one has a flickering display. Which they tell me is normal. But the other 3 didn’t do that….. The MCS is perhaps the worst and most pointless part of the y2k and later ML. Oh, and BTW, when the “technician” removed and replaced the first one for the 2nd one, he trashed the wood cowling and poked a hole in the plastic. Nice. Real nice. Of course, this necessitated a separate trip to have that replaced.

That aside, I’m guessing yours is (still) covered by warranty. They can swap one out in about 10 minutes. Call first to be sure they have one or more in stock…

[Kuan]

Tracy, you know of course that the other three didn't do it because they were defective! So now you have one with a flickering display? D'oh...

Kuan

[Lebenz]

Oh, yeah, a cool thing about the y2k ML and later is that if you leave almost anything on with the engine not running or the key off, the device will shut itself off after about 30 minutes. This works for the front cabin lights, and the MCS, at least. Of course, for some reason this won’t work with the light in the rear if you leave it on always on position. I found this out the hard way (that is, the radio, front cabin lights and rear light) as I have a bad habit of leaving doors open, especially after the return trip from a day on the slopes.) BTW, did you try turning the MCS back on? This is done by pushing in the volume button…

Kuan: They said it was “normal” and due to the alternator cycling. After so many defective MCS systems, I decided to live with it for a while, until they update the MCS, that is. The MCS actually gained some minor features over time, and I predict it will continue to do so. . .kind of like the ML itself

[Gilly]

I've seen these lock up like this a few times. if you had the tools to do it (radio keys) I would suggest R&R the radio incl. disconnect the connectors and see if it were happy then. In lieu of that, you could either try locating the fuses for it in the fuse box (list is under the lid) or even disconnecting the battery if you wouldn't mind resetting the time and trip computer (if you have it). You will also need to turn the steering wheel lock to lock a couple times to resynchronize the steering wheel angle sensor for the ESP. Just disconnect it for maybe 10 seconds or so, not a long time. It's easier to disconnect the positive cable, but just take the usual precautions you would take when working on positive post with the battery live. Or it's not "terribly" dificult to remove the negative cable either.
Gilly

[tgrand]

Well here's the update. Turn it back on? LOL. Tracy I would never admit to that. I tried that, the Navigation, phone, CD and all the other buttons that only my eight year old understands. Nothing. I pulled, checked and replaced the fuse with a different one. Nothing. So I check back with all of my Mercedes friends and read Gilly's post with great interest, and Tracy's with dismay. So I ran out and disconnected the battery, the negitive is pretty easy to get to, and low and behold we have tunes again The battery was the next thing I was going to try anyway but I didn't know about the ESP. Thanks

Tracy, maybe you and Casper and the gang need to come out to Colorado for some of our 300+ days of sunshine, sounds like you have a grumpy radio.

Todd

[Lebenz]

Gilly scores another one! He has the best track record of any ML tech I know. Gilly, move to Seattle, we need you! Believe it or not, they tried that (removing the power supply and fuses) on mine. They said that they replace the MCS with “factory” refurbished models. It says a lot.

Todd: I would dearly love to come to Colorado, if only to make half a million or so turns on the slopes. Last time I was there, I caught some of the sun and warm weather -- in the depths January.

Hope you enjoy the ML!!!

[Gilly]

Todd and Tracy:
Glad this little trick worked out. We haven't has MCS probs like this for quite awhile. I almost think there was something in print about the problem. It may have related to a software glitch, something about -don't turning off the MCS, then shut off the engine within 3 to 5 seconds, something like that. We get bombarded with so much info I'm lucky to remember where I live!
I also belive they said to R&R and disconnect the radio to reset it, probably to avoid having to monkey around with everything due to a simple battery disconnect, but since I didn't think you'd have radio tools, I figured it'd work OK.
(to clarify, I believe they in effect said "when manually turning off the MCS unit, wait 3 to 5 seconds before turning off the ignition", most folks I think usually will just shut off the ignition and not bother shutting off the MCS as a seperate operation).
In regards to the comment about "factory" refurbished MCS units, it is extremely rare to obtain a new MCS, or any other radio device. When under warranty, what we are usually required to install is a "warranty reman" unit, which as the name impies is a reman unit (by the manufacturer of the unit) which is installed as a replacement for an in-warranty situation. About the only time we ever see a "new" unit is if the original is stolen or otherwise not available for a warranty or core return.
Happy Moteren
Gilly
ps If I get time, I will try to research the "locked up MCS" tech bulletin and report back, and also thanks for the kind words.

pps Tracy: Just curious if it is a habit of yours to shut off the MCS, then shut off the ignition? Maybe that's all the problem is!

[Lebenz]

I always just shut off the ignition. Well sometimes I shut off the ignition and then turn on the MCS (CD player). This has never failed. I have forgot to shut it off in this circumstance more than once, and thankfully it always takes care of itself. The problems I had previously were sequential: Took the first one in, they replaced it on the spot, damaged the wood in the process and sent me on my way. The first one died about 2 hours later while on a 120 mile trip. Brought it back the next day and they pulled it out, pulled fuses out of the back, replaced them, reconnected and nada. Pulled it out again, and replaced it with the 3rd unit. That one was great except that the volume wouldn’t go up very much. I returned after a couple of weeks and mentioned this. The tech said that he measured the pre amp output and found it very low. They replaced the MCS again with the one that has a flickering display, along with new wood trim.

BTW, they told me that the MCS was a $5K item, (a little over 10% of the value of the ML(!!!)) and that’s the reason for the reman replacements. Personally I don’t have any problem with that in the abstract, it is just that the QC is obviously lacking. Since this series of replacements, about 1.5 years ago, it’s been fine except for the flickering display.

[Gilly]

I found the paper trail I was thinking of on malfunctioning "black screen" MCS units.
The first one acknowledged the problem, the temporary fix is to pull fuse f21 for 10 seconds to restore the MCS to operational status. They said this is the temporary fix, they were working on a permanent fix. That one was date 4/4/2001.
The next one is a bulletin that mentions updated MCS unit part numbers, so maybe Tracy wants to find out which part number they used.
On a 2000 MCS, the "good" number is 163-820-21-86-90 (for a reman, no "90" for a new one) The previous part number was 163-820-04-86-90.
2001's are a different number, a "good" one is 163-820-24-86-90, there are 3 prior numbers on a 2001, either 163-820-08-86-90, 13-86-90, or 16-86-90. If the truck is equipped with the MCS nav unit or in-dash cd player, the drive unit is transferred into the reman MCS, just so you know.
This second bulletin was issued Aug 9, 2001.
2000 and 2001 MCS units are NOT interchangeable.
Tracy, you may want to look back also and see if that last MCS was installed prior to August 2001, if so, you may benefit from bringing this info to the dealers attention.
Todd, I think you may want to talk to the dealer about your "black screen" event and see if you shouldn't be looking for a different MCS as well.
Gilly

[Lebenz]

Gilly,

Thanks so much for researching this! BTW, to your experience, should the LCD display flicker?

TIA

[tgrand]

Gilly,

Thanks for all your time researching this topic. I will print this out and keep it in the truck so that I can bring it to the dealer's attention next time I'm there.

[Gilly]

Tracy and Todd:
No problem.
Tracy, I don't think it should flicker, that's kind of why I mentioned it to you, and mentioned the numbers. If they put the older part number MCS in there, maybe they can throw in the newer version and fix that flickering problem. If the repair was done prior to August 99, they very may well have had to install that older part number MCS.
Todd, I believe I sent you a "PM" about this here at mercedes shop, be sure to pick it up and read it in regards to specific bulletin numbers, you'll want to mention that number to help them sort out what you need.
Gilly