Driving on highway about 65 to 70 mph, my SL abruptly slowed down to about 40 mph & wouldn't upshift higher than 5th gear causing following cars in haywire & I almost rear ended by multiple cars, tried to speed up to pull over to side of the road but gas pedal won't have effect even it was pressed down to floor all the way.

Another couple incident; driving along with traffic on highway, more like stop & go traffic, gear stuck on 3 & 4th gear and won't upshift, rpm goes up over 3000, no effect on gas pedal, basically crawling duck on highway waiting to be struck by other flying by traffic--- I got this on video (Mercedes dash cam won't record instrument cluster data on it's saved video & I had to install additional dash cam)

No warning or malfunction light at all when these happened.

Dealership could not duplicate issue in 2 service visit and this happened 3rd time in a raw last month & my SL is back in dealership

My SL 63 is 22 model & only have 2900 mile

Those who driving or own this car, I must warn you to watch out for this to happen & prepare this may happen anytime without warning, drive carefully with enough distance to make lane change!

I've been loving this car but now this car is safety hazard & not safe to drive around anymore

I reported this to NHTSA

Video link is here;

 

This is what annoys me most about contemporary high tech cars. They can suddenly revert to limp mode, and other road-rage prone drivers think you're messing with them. Cars equipped with limp mode need to at least auto-activate 4-way flashers while you're trying to get off the road safely.

 

and if no code is thrown techs are near completely helpless…

 

Yikes I'm so sorry OP, very curious what happened that caused the limp mode, it is sad that there is no DTCs stored for troubleshooting, I wonder if it was a fuel delivery issue, or some sensor data out of whack.

 

23 SL63, now about 8,000 miles. I have not had any of these problems exactly. I did have an event occur that was similar. I was in a lane with concrete barriers on both sides. The speed limit was 55 there. On my right side, past the concrete barrier there was a parallel street. I assume the speed limit there was 25mph. Anyway, my SL rapidly slowed to 25mph, while a 25mph speed limit sign icon showed in my HUD.
I don’t remember it being uncontrollable. After a startle response, I was able to make the car do what I wanted it to do.
This whole thing is just another example of the problems with algorithms, and this whole push for A.I.

 

Something sort of similar happened to me with out SL43 AMG press car.

https://mbworld.org/forums/sl-class-...ml#post8943095

"We had a press loaner and the SL43 thought it was about to be in a front end collision (empty road), then threw all of these warning codes and failures on the dash. I turned the car on and off at the next light and everything was back to normal except a check engine light. The next morning, after the vehicle sat in the garage all night, the check engine light was off and back to normal like nothing had happened, and it never did it again..."

 

Darn, that is very scary. Glad to hear both you and OP remains safe. Frustrating the car decides to not report a DTC, you don't even know what exactly happened.

 

I know that location. 100% unacceptable. Lives at risk and just another day for Mercedes.

 

Hello, I had a very similar incident occur last year when I picked up my CPO 2022 SL 63. The dealership is located about 700 miles from where I live in WI. The car ran perfectly for about 100 miles (of course) from the dealership, but then I had the same lack of power issue and non-flashing check engine light came on while driving on the OH turnpike. If I recall, the max rpm was about 3000rpm.. The car would eventually make it up to 65 mph or so after literally an eternity. It would lose speed on hills. I nursed the car all the way to Chicago and stopped for the night at my 2nd home. The next morning I decided to try to make it back to W. WI. (400 miles). It was running worse at initial start up, and briefly had a flashing check engine (bad news). It settled down, and I decided to risk it when the flashing check engine light went off, and made it all the way back to W. WI. What I think was the problem was bad/old gasoline.

The car was a year old, had 750 miles or so on it after almost a year after its inital purchase by the first owner. I kept stopping frequently to add more new gasoline and as i did that, it was running normally by the time I got it home, but with a solid check engine light. After a few days and more "new" gasoline, the check engine light went off and has remained so. I'm taking it in next month for an annual service, and we'll see what they say about it. Bad gas especially if it contains ethanol is a real possibility at least in my case.

It was very scary merging onto the Kennedy Expressway in Chicago at 35mph with my foot in the firewall!

 

Sorry to hear that, I am starting to wonder if it is a coil issue.

 

Reason why I mentioned coil/ or fuel injector it is because I remember reading about a forum member having this exact issue and it turned out to be one of those mentioned, hopefully it was just a faulty coil or injector and the car is fixed after that, here is more on the story: https://mbworld.org/forums/sl-class-...ml#post8951811

 

You have a 22 model? Let your dealer do all those due software updates...

 

I had a similar experience yesterday, driving east from Asheville NC on I-40. There's a long, long twisty downhill section, with some roadwork. The speed limit varies between 45 and 55mph. However, every few hundred yards there are "Truck Speed Limit 35mph" signs. On passing those signs, the SL cruise control sets the speed to 35mph and applies the brakes. There's a setting buried in the menus to ignore speed limit signs, but fiddling with settings while driving on an unfamiliar, twisty, crowded road seemed like a bad idea. The easy fix was to turn off the cruise control and, you know, actually drive the car ;-).

As an aside, some very unlucky people in a camper van hit an even unluckier large bear near the bottom of the hill. Very ugly for the camper van, a shock for the people, and a very bad day for the poor bear. And I thought that deer were bad...

 

Oh no, poor bear : ( Obviously I am wrong but is that a reason why your forum name is FlyingBear? Are you that poor bear : (

 

Very true. If you are an experienced driver, set up the driving assist features to the least sensitive setting or turn them off completely if you think you don't need them. I do not use lane assist because it sometimes interferes with my driving style. Same goes to the emergency braking assist, I set it to "late" (least sensitive setup) and it still messes up my driving sometimes because it thinks I am going to hit something and it applies an emergency braking (not kidding, a guy behind me almost crashed into me because of that). I think that Mercedes should offer a more simple setup for ALL systems like "track driving", "very experienced driver", "not so experienced driver" and "novice".

Why I do not turn off emergency brake assist completely? Because it can really save your ***, even if you are an experienced driver. I once exited my parking spot in reverse, extremely slowly (basically in ultra slow motion mode ) and a stupid bicycle rider came at a very high speed (it was a 30 kph zone, he had at least 50 kph according to a witness behind him) and almost hit my car. My car applied the emergency brake (it was impossible to see him, I watched the rear camera which does have a wide angle view but the bycicle rider came at a very high speed) and the bicycle rider apparently got startled, hit his brake and fell from his bike. My car didn't touch him. Still lucky me that there was a car behind him who witnessed everything. Not sure if the 360° camera system of the SL recorded this, there was no indication but maybe if the bike would have hit my car. Thank god nothing serious happened, that guy on the bike was OK (at least he was wearing a helmet) but in the beginning, he tried to blame ME. Witnesses are worth gold in such situations and of course the emergency brake assist which seems to work even in reverse.

 

Here in south coastal Orange County, CA where I live, the electric bicycles and E-BIKES have absolutely exploded in popularity. Unfortunately, most have been bought by what I feel are disengaged parents for their “tween” kids who ride them with the youth mantra of “NO FEAR!” I have paced these idiot kids at up to 50mph as they blast down sidewalks. Put a hill into the equation and I’m sure 60mph+ is easily within reach.

They ride these things with absolutely zero abandon, right next to parked cars, blasting right into parking lot aprons, coming seemingly out of nowhere. As an older fellow, I find myself having to not just look “both ways” as I was taught so many decades ago, but “every which way,” as the riders ride against the flow of traffic, on the street, on the sidewalks and going WAY too fast, not to mention roaring right through STOP signs and red lights! Little 14 year old girls, riding virtually naked, with a friend on the handlebars, as they both are texting. I’ve never seen so many, potentially disastrous scenarios for kids in my entire life. No helmets are required and as of right now, no licenses or insurance are required and these are ELECTRIC MOTORCYCLES!

Lastly, these E-BIKES give young kids the ability to quickly & easily get far away from home, into areas where they are way out of their safety zone. If your kid is pestering you for one, think a THOUSAND times before you give in.

 

Folks are discovering that self-driving features are not designed to learn a driver's style and emulate it, but rather to adhere to traffic laws and to sometimes irrational algorithms. More and more drivers will be disabling as many of these assist functions as possible as they gradually discover that they interfere more than they assist.

 

If the AI in these cars can't make sense of the signs and laws what chance do stoopid people like me have? Anywho, I'm 100% sure the solution to too many signs and too many laws is going to be more signs and laws. Here in Texas they even have a sign telling you to obey the other signs. I sheet you not!

 

The signs that I find annoying are those posted in 50 mph zones to inform you the speed limit within the city limits ahead is 25 mph unless otherwise posted. Guess what the car does.

 

I'm glad to confirm that I was not the bear in question. I do like bears, though.

 

Convoy
C.W. McCall

By the time we got into Tulsa Town
We had 85 Trucks in all
But they’s a roadblock up on the cloverleaf
And them bears was wall to wall

 

Gotcha, ya I feel bad when I see road kills, reason why I refuse to drive at night, don't want to be one of those drivers that might accidentally/unintentional kill one.

 

happened to me also. Sl 43. The problem reapeared. Where are you from?? When this did happen??

 

this has happened to me two or three times now, each time almost resulting in a rear end collision into my vehicle. Dealer have vehicle for a month and found nothing to be wrong and returned vehicle. I’m always paranoid when I drive it now it only has 2200 miles. It’s a pleasure car. One of the incidents was in an inactive train track.

 

That “DIP” sign is only half a sign. You are missing the other half. You already me what the other half is. It applies to Texans, but applies more to out of staters.