Has anyone else experienced a lurch/forward jerk like movement in situations where you're in drive and you might be in a parking situation where you only want to move the car in very small distances, like inches at a time? I think maybe it's a weird transmission negotiation issue of the vehicle switching between the 48v system (GLE 580 MY20), engine, and auto star/stop maybe? It could be quite troublesome if you're in a tight parallel parking situation where you only want to move a few inches and instead it lurches/jolts forward like 2-6".

I'm experiencing this in my tight garage where I need to park my car at a very specific line otherwise I can't close the garage door in the back and don't have room in the front to walk around the car. While parking in my garage, I'll put my front bumper camera on and inch along until the bumper reaches my specific line, all of a sudden this lurch/forward jerk makes me overshoot it. It's really annoying because I then have to backup.

 

I have a 450 but have not experienced any of those symptoms. I do not believe it is related to the 48v system or auto start/stop but I suppose anything is possible.

 

I think I have this but not sure. Is like at stop and slowly on the gas pedal car jump launch. Not sure I will monitor this more

 

My GLE experienced the same thing. Trying to crawl the last few inches in the garage can be nerve wracking sometimes. Usually no throttle while in gear provides a relatively consistent amount of movement, but not for my GLE and feathering the throttle will sometimes cause the car to jump forward no matter how lightly you try and press it. I think it is the transmission and the first gear or whatever gear it is on during these instances. My S class is the same, although not as bad. It just feels very inconsistent in these slow speed situations.

 

Make sure you are in D1 and then try blipping the gas a bit with your foot firmly on the brake. This should ensure the car isn't thinking about to engage auto stop and that there is some pressure in there. Then slowly release the brake to inch forward.

 

I was thinking maybe I just have to turn off the auto start stop when I'm in those situations. Easy to remember when parking in the garage because of the strong association with the location but not always easy to remember when you're on the go. I'll give it a go today and see if just turning it off helps.

 

I always have auto stop off.

 

it sounds like a trip to the dealer is necessary. the auto stop/start should not be the cause of the problem or needing to blip the throttle. The latter sounds like a recipe for disaster even if you are pressing the brake. Maybe a transmission relearn is necessary.

 

This is what I was going to suggest. I have not experienced the issue, but based on your description I think there is a good chance it’s auto stop related. Good luck.

 

I've not had that in my garage--I always turn off that auto thing until just before I put it in park. I've not had it anywhere actually.

 

@wildta have you tried different settings - Comfort, Sport etc?
​​​​​​Can you see a display that shows your actual gears?
​​​​​​Does your gas pedal move freely?

 

I've only tried comfort, gas pedal moves freely, I haven't taken notice of the gears but will try to next time.
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Parked today with auto start stop off and was able to creep very slowly into my garage at my specific stop line and it worked great so it's definitely an issue with the auto start stop.

 

Took vehicle to dealer today, they said it's "normal" and even my advisor who owns two MBs and was a tech for VW for 8yrs said he keeps his Auto Start/Stop off in those situations.

 

Lurching is not normal. I would try going to another dealer if you have the option.

 

​​​​​​If that's true, then a battery's State of Charge might have an effect on other people's experiences.

​​​​​​If a battery is fully charged, the car will readily shut down, only restarting when low on charge, or the accelerator requests. Sounds like you're there.

Others who "never experience" it might have lower charged batteries that don't let the engine shut down, so no Restart on acceleration.

So maybe both are "normal."
​​​​​​​Just thinking out loud.

 

Seems feasible. Just wish MB would program the Auto start stop to be disabled in these tight parking scenarios since our cars have all the sensors to detect such situations, especially if you have the park assist feature.

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Could it be attributed to bad engine mounts? A friend mentioned this to me and do this test for engine mount test which I'll do when I get my car back.

Update: Engine mounts are fine.

 

Just wanted to revive this thread because I read this post where that owner had their EQboost motor/starter assembly (is this the ISG?) replaced. Just wondering if I should push my dealer into replacing mine to fix my issue as mentioned above.

 

This is absolutely a side effect of auto start/stop and will happen on any vehicle some more noticeable than others. The ISG is much better at minimizing it than a traditional starter but it will still happen. Think about what the car sees:

• You're coming to a stop with very light pressure on the brake with the engine running and providing torque
• The car doesn't know whether you intend to stop for a stop light, parking space, or other so it may engage and shut down the engine (no more torque)
• You release the brake to creep forward or backward, now the ISG or starter must refire the engine and immediately begins providing torque while you've released the brake.
• With no brake force the car will jump forward or backward slightly before you re-engage the brake.

Obviously the solution here is to disable start stop when parking. There are a number of things that could be implemented by MB engineers to combat this, but they clearly haven't. I've noticed this effect in all vehicles with start/stop in very slow moving situations. The effect is much worse with a traditional starter vs the ISG.

All that said, when coming to a stop where start/stop should engage the transition is pretty good. Much more seamless with the ISG than a traditional starter.

 

I don't believe any of those things should be happening as you described.
The engine shouldn't shut off when you are moving around, unless you're coasting. I doubt that you're coasting into a parking spot.

And the car shouldn't "jump forward" when you release the brake.

Unless I misunderstood your description, it sounds like there's something wrong with your car.

 

There is certainly a timing element to it and depending on driving habits I'm sure some people may not experience it. I don't get it regularly, but when I do it's because I'm just about to come to a complete stop and then lift my foot off the brake to continue forward slightly. This is a learned behavior that I've used for 25 years to come to a complete stop and smoothly unload the suspension. I feel like auto start/stop gets aggressive sometimes and decides to stop at the same moment I'm lifting off the brake which then triggers an immediate restart. While I would call it a jolt and not a jump, I can see how some people would call it a jump. In any event, when it happens, it isn't a smooth transition. In response to this behavior I've altered my behavior to come to a more deliberate stop when start/stop is active.

 

This is a better description of what I feel. It's almost like a rolling stop where I brake to around 1-2MPH, somewhere at this moment the engine turns off. Then when I lift off the brake, the ISG engages and gives me this jolt. It happens in stop and go traffic, stop signs (when I do a rolling stop), and traffic lights.

 

I never noticed anything of this nature. My garage is pretty tight, a few inches on both sides, so, I’m just rolling into it at 1-2mph, nothing unexpected at all, same for parking at public garages / parking spots or backing up to connect a trailer. We have different ISG version(Gen 2 on 2024) but it would be weird if earlier ones behaved much different. Like, it should not be pushing you forward abruptly if you barely touch the pedal.

What I do is pushing the throttle ever so slightly and dropping it right away, moving the foot to the brake pedal just in case. Never had to use it but a bit hard to imagine somebody overshooting by a foot, like you have to control how the vehicle moves by being ready to apply the brakes.

 

Just wondering if I should ask my dealer to try to look into replacing the "EQboost motor/starter assembly" like what another user had replaced as described in their post that I linked above.

 

You can try to have them replace it, but I doubt it will eliminate what's happening. The real solution is to decouple the ISG from the ICE engine so that it can provide drive power without starting the ICE engine. This would allow it to shut down the ICE engine and still allow slow forward momentum. That's probably coming in the future.