Markus03

I was in 'C' mode at a red light and then when the light turned green, I started moving, as usual. I noticed when I got up to about 70 kph, the engine was really over-revving and the red warning light flashed to switch to a higher gear. Because I thought I was in 'C' mode, it took me about 5 sec to realize that I was in 'M' mode and in FIRST GEAR!

I can't believe that the transmission automatically switched from 'C' to 'M' without me doing anything at all. Has this happened to anyone here? Also, I'm afraid that I may have damaged the engine running on 1st gear (redlining for about 5-7 secs) up to 70 kph.Your input would be greatly appreciated!!

enochroot

I've done this in just about every car I've ever had - your transmission and engine are fine.

It won't let you damage the engine or transmission, it will always switch to a higher gear to protect itself.

Thankfully the engine and transmission are much smarter then we are.

Yuille36

My friend, your stressing over nothing, so don't worry. Now if you drove like this for miles, then yes. But 5-7 seconds, no problem. The car will not let you over rev it, even though the car redlines at 7200 rpm, the electronic nanny will not let you actually get there in 1st gear. Your shift light will come on like 7000 rpm, a 200 rpm sooner to protect the engine. The other day, I got on my C63 hard, the shift light came on well before I got to redline, it looked like 6800 rpms to me. Although I just glanced down for a second, and didn't actually see the rpm needle clearly. But, I beleive 6800 rpm is redline for these cars in first gear.

BIGjohnny

Engine won't automatically upshift in M mode. Despite whatever rpm you're at.

To Markus03. Engines nowaday, especially AMG, can handle high rpm for a very long time. When i'm out on the track with other AMGs, M3s and etc... were all driving at or near redline for minutes rather than just 5-7 seconds. So don't worry about it and just relax

Yuille36

Markus03,

The car is tougher then you are

IAA-C63

And now you also know how fast your car can go in first gear.

mthis

Your car is fine and when your car is in any type of danger it will go into limp mode (only use of 2nd gear and reverse for sometime then if you continue to drive in limp mode it will shut down)
you cant get into limp mode by just holding your rev's in 1st gear the only thing that will happen is M will start acting like S and switch on its oven. (so YES M does up shift on its oven when its getting alot of abuse)
BTW i know this bc it happened to me.

HuangYiChao

Dont worry. In my M3 i was blasting music once in traffic and I had my car in first gear for about 20 sec at 7500 RPM. Keep in mind my car is manual and I didnt notice the traffic was getting faster until the jerk when I let off the gas.

Markus03

Thanks guys for all your input! I can sleep better tonight!!!

optiguy

A friend of mine was an engineer for Allison transmission. He told me Allison bought a Mercedes and they were told to find the week points in the transmission. After repeatedly abusing it and slamming it into gear at high rpm, they gave up. They were unable to tear it up through driving.

jafores

I think the red upshift light comes on earlier in first gear. Maybe it is programed that way so the driver can upshift earlier and because of the delay of the autobox catch the upshift before the rev limiter checks in beyond 7200.