VaclavSV

So on Sunday I was out at the meet we had here in the GTA. (It was a great time to meet lots of you on here) Anyways when I was on the highway I floored it from 7th in S+ and noticed my gears didnt change down. I then braked and noticed the car display stayed in 7th gear. I then tried shifting down manually with the paddels and still nothing! I took the next exit of the highway and it stayed in 7th the whole time. I tunred the car off then turned it back on. At first when I pressed the gas the car wouldnt move... I was terrified to say the least. I put in in Neutral then switched to M back in Drive , it defualted to first and I felt a whack of gear changes as the car jerked forward. I then put it in C and drove normally wathcing the car climb up and down through the gears. Everything seemed to go back to normal but it was very very odd to have happened. Anyone know what went on?!

Z63amg

I have heard that they are having more and more issues with the MCT tranny. This coming from a dealer.

CoolBDPhenom03

Yikes! Let us know when you have it diagnosed and a "cure". I hope it's not a big issue. Would resetting your TCU do anything?

EkS

I would check to see if there are any stored fault codes.

VaclavSV

I have service B booked on the 23rd so I will have them look into it!

antman0505

I had a problem with my MCT the other day.

I started the car and noticed that the transmission mode selector dial indicator wasn't lit up. I then tried changing modes without any effect. The dashboard display showed I was in C mode. I tried turning the car off and on (but I didn't hop out and lock the car) but still no joy with the selector. I drove off and the car behaved normally as it would in C mode. Unfortunately still unable to change modes.

After I got home I shut everything down and came back a few minutes later, restarted the engine and everything was back to normal! A week down the track and no further issues.

Rsquad911

To eliminate other causes....

Do you switch between C S S+ to Manual while moving?

Only issue I've had with my MCT is in M mode 1st gear once and a while it's very jerky... I'd have kinda floor it to smooth it out (but I'd be kinda peeling tires)

Fung63

How is it today? if its a tranny problem, I personally wouldnt wait the week. MB will make room for you.

VaclavSV

The car is actually in the shop getting paint this week but everything seems normal. I have no idea what might have caused it.

Rsquad911

Paint? Owwwwww! New body parts you haven't told us about?

Fung63

He mentioned at cars and coffee that he was blacking out the chrome... maybe that's it

SLS Qatar

it may require a software update .

alrasheed1991

shaklo wa7ed sakoh be3eeen allah yester bas men al3een

I would let dealer check it sorry to hear that

FrancisVol

This coming from a dealer.

VaclavSV

Yes Im blacking out the chrome! The Chrome LEDs were bothering me way too much! haha

As far as new body parts Im close to adding the Vath grill Im just waiting to see what boca comes out with in regards to their CF grill for the 2012s... they said they shoul have pictures soon, as well as a CF vented hood for the 2012s!

Fung63

+1 on the CF vented hood. Will make your C63 much more aggressive

VaclavSV

My service advisor sent me this in response o my email

I reviewed this with our shop foreman, he suspects the vehicle went into a
"Limp home Mode" and that there should be fault codes stored. We will need
to check the codes to determine what the issue was.

Has anyone heard of "Limp Home Mode"????

OCJeff

I think they are referring to transmission limp mode. From over heating.

NORTH 44 C63

I had the exact same issue and sequence of events the second week I had the car. My shop foreman did a scan a few days later without and codes stored. Has not repeated and I am at 15,000 Klm.

VaclavSV

The shop foreman and service manager called me while the car was in for service B. There were some error codes and they have to replace a valve in the transmission (Under warranty). The part was on back order (Maybe its a common problem??) so they said about 5-10 days before its at the dealer and ready to be replaced. They said the car was fine to drive and I will be picking it up tonight. Does anyone know what this valve does in the transmission? Is it a fluid thing?

Ps. I really hope this doesnt mean I have to do another 1500km break in!

EkS

Can you post the error code?

VaclavSV

I will ask when I go to the dealer at 5 and see what information I can get!

VaclavSV

0606
2768

rory breaker

Will be interesting to see if that's a legit diagnosis or one of those "hmm we can't recreate it and don't know what causes it...so just replace that thingamajigger and let's hope it changes!" situations from the dealer.

VaclavSV

The dealer did a very extensive diagnosis. In the morning I went on a drive with the Shop Foreman and showed him my concerns. The report that they went through was a good 60+ pages. They found the fault codes that indicated one of the valves in the terminal that changes electrical signals into mechanical power was sticking. They will replace the terminal unit when it arrives. As for currently driving the car its fine and if it were to stick again I would just need to turn the car off an on... mind you it hasnt stuck in a gear since last week.