wes459

So my wife and I are headed back to NC from AZ, and up until today, the car has been great! We got slowed in evening traffic headed out of downtown KC, and suddenly my dash info went crazy with ESP and ABS warnings, followed by a Display Malfunction warning as well. I figured we could make it to a gas station and I'd figure out what was going on, but before that I got a red alert that said something about Engine Stop, Coolant Warning (or something thereabouts).

I limped to the gas station and turned the car off...mind you nothing sounded or seemed out of place... and then the car wouldn't restart. I waited about 45 minutes, and then it started and I put it into gear so I didn't have any other problems. We limped for about an hour (10 miles...) over to the Merc dealer, but the weird thing is that the whole time, the dash info was scrolling through warnings, but then would clear and the car would drive fine again, it went haywire multiple times on the way to the dealer and locked into third gear, but then would act like only the check engine light was on, with no other issues driving normal.

We'll see what the dealer says in the morning, but I'm hoping that it is some sort of dash display malfunction and that's it.

Cheers to KC AMG owners!

JDM_SXE-10

Good luck. I hope things work out for you. It's a horrible feeling being far from home and having car problems that you can't figure out. It has happened to me before.

Enigma94

Being locked into 3rd gear means it's gone into limp mode which is not good, unless it's a faulty sensor that's causing it to gin into limp mode. Hopefully they can figure it out without you having to bend over at the end of it all!

wes459

That's what I figured, but then it would go in and out of limp mode on the way. I'm hoping that it isn't something crazy and I can get back on the road tomorrow!

justinwrock

Can you check your voltage?

A bad alternator will cause all sorts of weird issues.

E55Greasemonkey

Sounds like the alternator

wes459

No way to check the voltage...I took a cab to a hotel a few miles away in the hopes that they can take a look first thing in the morning.

I called Denroll, and he brought up a good point to have the CEL code checked, but I didn't run across an Autozone or what not on the way to the Merc dealer, and my wife was a little freaked out that the route we took was through a rough neighborhood...lol. I took the straightest route to the dealer possible to hopefully catch a tech before they closed...

berti_00

Sorry to hear bud, hope it's nothing big and your back on the road... Good luck

G_Money

Voltage regulator?

Yacht Master

+1 low voltage, and we all know Low voltage kills....

And yes there is a way to check your voltage, on the way to dyno mode.

wes459

Yeah, I tracked it that way when I got the car back. I left it at the dealer overnight though.

So here's the update:

We made it home at like 3 AM this morning!!!

Chris at Mercedes Benz of Kansas City had it looked at first thing yesterday morning and from the codes that he obtained, he said the ECU was fried. I asked him if he flashed the ECU back to stock if it would make a difference, or enough for me to get home. He said he'd try but with no guarantees, and to stay out of boost!

Turns out, the car had no issues until we were about 300 miles down the road. Then it started the ESP, ABS, Display malfunction again, with all types of error lights. The dash stopped working again, but I figure the car was running fine mechanically so I'd keep going. About 10 minutes later, the dash started working again and even the CEL cleared itself. I stopped to get gas in this moment of no errors, and then turned on the voltage monitor thing in the service screens.

Before starting the car it read 12.2 and after starting the car, it varied between 13.8 and 14.0.

The error sequence occurred 3 more times on the road, each time completely clearing itself. When I got home, I plugged in the EuroFlash software to read for any codes, but there were none. So I plugged the car up to the charger over night.

When I got up this morning, I flashed the performance tune back onto the car, and after about 25 minutes it went to 100% with no errors. I drove the car for about 15 minutes around town and got back into boost a little bit and haven't had an issue.

I'm guessing it may have been a voltage issue as well, everything happening was too weird to be just an ECU issue and still have the car be able to operate at 75 mph. I'm ordering a new voltage regulator, and potentially a new battery. I also plan to call Eurocharged in the morning to see if this is something they have seen, in the event that my ECU is "going bad".

I do want to thank Chris at MB of Kansas City for not charging me at all, he said it was dumb to charge me for something I essentially already knew...and for washing the car as well!

Thanks you guys, and I'll be sure to keep you all up to date!

StarvingArtist

I don't think your battery could cause that, but just for reference mine holds 13.2V and it's 8 years old. Maybe the VR is on it's way out and the battery can't make up the difference. Maybe check the connections on the ECU

naudi

Mine acted this way when the voltage regulator was getting short making little to no contact. How many miles on the car?

wes459

141k

G_Money

Yeah, the voltage regulator is such a quick and easy DIY, it's almost worth it just to do as a process of elimination.

And it seems to me if your ECU was "fried" you wouldn't be going anywhere at all with your car until you had a new one.

naudi

Wow and you still have the oem one! Mine was to short at less than 100k. You definitely got your money a worth! You will be shocked at the size difference when you see it.

novae500

So the ECU was fried?? NOT.... Probably your VR as others have said, or possibly the alternator itself.

wes459

I've got some work to do this week in Burlington, so on the drive over I called the dealer in Greensboro and they hooked me up with a new VR. The guys at allmotorwerks.com emailed me this morning and said they no longer sell parts. I'm going to try and get the new one on this week, but at the latest it will be this weekend. The car seems to be running great again though, and I didn't have issues on the 2 hour drive from home.

I do want to give a big thanks to all of the help and advice you all have given me! This is an awesome community to be a part of! Special thanks to Denroll and Thunderclap for getting me hooked, and all the help they gave me while I was in Arizona