Steering jerks as car slows to a stop

[jnthn98]

After owning my MME for about a week, I noticed that whenever I turn the steering wheel ALL the way to the left while pulling out of a parking spot, I experience some jerking/vibration as if something is rubbing or not turning smoothly. So I would step on the accelerate pedal while turning a sharp left (at low speed), then let go of the pedal (while the steering wheel is still turned all the way to the left). The car would slow to a stop (with one-pedal driving turned on). Right before the car comes to a complete stop, the jerking/vibrating occurs and I can feel it in the steering wheel. The jerking happens 2-3 times before the car is stopped.

Does anyone has this issue or is it normal for MME? I've never felt this with other cars (came from a Bolt EV). Due to the nature of my parking spot, I haven't tried to duplicate this setup with an all-the-way-to-the-right turn yet, but will find a big open parking lot to try in the near future. Thanks in advance for the feedback.

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[JCHLi]

Assuming you have eAWD version?

 

[JamieGeek]

Yeah I've had this happen in mine too (note CA Rt1 so RWD). To me it feels like the wheel shaker used in the lane keeping system.

It also feels like a U-Joint at an extreme angle (which wouldn't make sense on my RWD car).

 

[ARK]

I park on the street and regularly make the same type of U-Turn turning left you describe where I have to turn the steering wheel all the way to the left.

I have never experienced this vibration that you mention, but also don’t stop after turning. Since I am on the road I just keep accelerating once the turn is complete. I will try to stop next time I do this just to test it. I also drive in Engaged mode with 1PD off.

 

[RonTCat]

After owning my MME for about a week, I noticed that whenever I turn the steering wheel ALL the way to the left while pulling out of a parking spot, I experience some jerking/vibration as if something is rubbing or not turning smoothly. So I would step on the accelerate pedal while turning a sharp left (at low speed), then let go of the pedal (while the steering wheel is still turned all the way to the left). The car would slow to a stop (with one-pedal driving turned on). Right before the car comes to a complete stop, the jerking/vibrating occurs and I can feel it in the steering wheel. The jerking happens 2-3 times before the car is stopped.

Does anyone has this issue or is it normal for MME? I've never felt this with other cars (came from a Bolt EV). Due to the nature of my parking spot, I haven't tried to duplicate this setup with an all-the-way-to-the-right turn yet, but will find a big open parking lot to try in the near future. Thanks in advance for the feedback.

It might be a just a weird point in the power steering calibration. I would report it. It might be "normal", but still an annoyance that can be fixed via OTA.

 

[dkmatter]

Ackerman effect?

Strange Noise/Sensation upon Steering Full Lock | Porsche Forum from Porsche Club GB

 

[jnthn98]

Assuming you have eAWD version?

I have a Select RWD.

 

[jnthn98]

Ackerman effect?

Strange Noise/Sensation upon Steering Full Lock | Porsche Forum from Porsche Club GB

Thanks. I read up on what "Ackerman effect" is. It does sound like a possible cause of what I am feeling. The article stated that most modern vehicles have techniques to migrate this effect (so people don't feel the effect) except for a few vehicles like the Corvette.

I do wonder if it was intended for the MME to have the Ackerman effect though. If its normal, I would think that more people on this forum have reported this issue. Or maybe i just haven't read enough posts on this forum.

 

[dkmatter]

Thanks. I read up on what "Ackerman effect" is. It does sound like a possible cause of what I am feeling. The article stated that most modern vehicles have techniques to migrate this effect (so people don't feel the effect) except for a few vehicles like the Corvette.

I do wonder if it was intended for the MME to have the Ackerman effect though. If its normal, I would think that more people on this forum have reported this issue. Or maybe i just haven't read enough posts on this forum.

Well, it happens on some Porsche and Audi cars too. If it is an "Ackerman effect" were in good company.

 

[ARK]

I tried my U-Turn yesterday, turning the steering wheel as far left it would go and coming to a stop out of the turn, I did not get any vibration. I have an AWD SR Premium.

That being said, I do not start turning the steering wheel until I am moving if that makes a difference.

 

[jsteach]

You might be engaging the steering stops. It keeps you from over steering or extending the power steering mechanism too far. When the stops bind and then having the suspension activate
over uneven surface you can get push back on steering wheel. Try, when turning the wheel all the way
then back off maybe 1 inch or so on the steering, should go away.

 

[jnthn98]

You might be engaging the steering stops. It keeps you from over steering or extending the power steering mechanism too far. When the stops bind and then having the suspension activate
over uneven surface you can get push back on steering wheel. Try, when turning the wheel all the way
then back off maybe 1 inch or so on the steering, should go away.

Thanks for the explanation. In my situation, I did turn my steering wheel all the way to the left due to my tight parking spot at home. Can you elaborate on what you meant by "suspension activate over uneven surface"? My parking area does have a little slope (not much). Are you saying that when the suspension is moving (due to the little slope), it affects the steering even more, which caused the jerks/vibration/push back on the steering wheel?

I tried to reproduce this issue/effect at an open parking lot, but I wasn't able to. I can only think of two differences between the open parking lot and my home parking space:
1. My parking space has a little slope while the open parking lot doesn't.
2. When I pull out of my parking space at home, the car & tires are cold. When I tested the all-the-way-to-the-left steering at low speed in the open parking lot, the tires were already warm. I think this sounds like the Ackermann effect where the issue is more obvious with cold tires.

 

[jnthn98]

So while I brought my MME back to the dealership to apply SSM 49730, I asked them to look into my steering vibration with the wheel turned all the way. They were able to reproduce it with my car, as well as another new RWD MME at their dealership. They said it's normal based on how Ford designed the steering/one-pedal driving system/iboost (I don't remember their exact words). They couldn't do anything about the vibrations, but said that if there's a future SSM on it, they would be able to work on it. For now, it's normal.

On a different note, my service advisor said they have just one other MME in their service department. It's an AWD that couldn't fast charge (at an EA station). After hearing this, it makes me want to DCFC my MME soon (even though I haven't need to do that within 1 month of ownership) just to make sure it works. Better find out now than when I am on a road trip.

 

[zhackwyatt]

I have it too. This is pulling into my house after driving from work. My tires were definitely not cold. It doesn't happen every time.