EPAS Terrible Shudder

From the 2011 Mustang owner's manual:

AdvanceTrac Sport Mode
The AdvanceTrac system provides an available sport mode on some models. This can be selected utilizing the stability off button as shown in the table above.

Sport mode is not intended for use on public roadways as this mode provides less AdvanceTrac system intervention than when the default ESC and traction control systems are on. Sport mode will allow more spirited driving while the AdvanceTrac is still enabled.

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Sport mode is a function of AdvanceTrac stability and traction control, not the EPAS system. EPAS is adjustable separately on 2012+ models.

I could have sworn I saw somewhere that the steering was put into sport mode also. When I put it in sport mode I can definitely feel a difference in the steering. I have a Brembo equipped car if that matters.

EDIT: After doing some searching it looks like there is no official word from Ford about the 2011's, but multiple people say that they definitely notice a difference in the steering when in sport mode. IMHO, the steering does change on the 2011's when in sport mode, it just isn't a separate selectable option like on the 2012+. Further proof is that I experience the shudder when in sport mode only.

We had the Vorshlag Mustang at another track event this weekend. This time we were on sticky tires and the EPAS issues were as bad as they've ever been.

We don't have a solution yet. New steering racks should be available soon and we will install one as soon as it's available.

applesauce683 said:

I could have sworn I saw somewhere that the steering was put into sport mode also. When I put it in sport mode I can definitely feel a difference in the steering. I have a Brembo equipped car if that matters.

EDIT: After doing some searching it looks like there is no official word from Ford about the 2011's, but multiple people say that they definitely notice a difference in the steering when in sport mode. IMHO, the steering does change on the 2011's when in sport mode, it just isn't a separate selectable option like on the 2012+. Further proof is that I experience the shudder when in sport mode only.

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I have a Brembo 2011 and notice absolutely no difference in my steering weight or feel when in Sport Mode. The Mercedes I work on have very noticeable differences when adjusting the steering feel so it's not that I am just not sensitive enough. Moreover, I've driven a 2012 with the steering set to Sport and could tell right away it was heavier.

Sky Render said:

From the 2011 Mustang owner's manual:



Sport mode is a function of AdvanceTrac stability and traction control, not the EPAS system. EPAS is adjustable separately on 2012+ models.

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Somewhat correct, it does however firm up the steering (akin to the seperated control in 2012-forward). For me its a notable difference in steering response and feedback on my 2011. both in sport, and advancetrack off modes (TC off seems to remain in default steering mode).

For me the shudder feedback is 10X when in sport mode, so much so that on the highway I just leave it off.

I have a '12 and can definitely tell the difference when toggling through the modes for steering feel. I have been leaving mine in sport mode now that i think of it, maybe ill just switch it back to comfort or normal.

Grimace427 said:

I have a Brembo 2011 and notice absolutely no difference in my steering weight or feel when in Sport Mode. The Mercedes I work on have very noticeable differences when adjusting the steering feel so it's not that I am just not sensitive enough. Moreover, I've driven a 2012 with the steering set to Sport and could tell right away it was heavier.

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Definitely interesting. Possibly later build dates had the feature?

captdistraction said:

Somewhat correct, it does however firm up the steering (akin to the seperated control in 2012-forward). For me its a notable difference in steering response and feedback on my 2011. both in sport, and advancetrack off modes (TC off seems to remain in default steering mode).

For me the shudder feedback is 10X when in sport mode, so much so that on the highway I just leave it off.

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EPAS is not at all affected by sport mode on a 2011. The owner's manual mentions nothing about this in either the AdvanceTrac section or the EPAS section. How many times do I have to say this?

If the shudder is worse in Sport mode, your traction and stability controls are apparently covering up the problem when in the default mode. Which leads me to believe it may not be a problem with EPAS at all.

Sky Render said:

EPAS is not at all affected by sport mode on a 2011. The owner's manual mentions nothing about this in either the AdvanceTrac section or the EPAS section. How many times do I have to say this?

If the shudder is worse in Sport mode, your traction and stability controls are apparently covering up the problem when in the default mode. Which leads me to believe it may not be a problem with EPAS at all.

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I respect your opinion, but just because the owner's manual doesn't mention anything, doesn't mean it is an open and shut case.

applesauce683 said:

I respect your opinion, but just because the owner's manual doesn't mention anything, doesn't mean it is an open and shut case.

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There is zero difference in steering feel on my car (or friends' 2011s) when I put it in sport or AdvanceTrac off mode. If you think there is one; it is a placebo effect.

Show me one credible source that says EPAS can be adjusted on a 2011.

Probably can say it all you'd care to, I'm certain of my findings.

we can agree to disagree then. I can perceive a noteable difference in feedback (especially with the shuddering on sweeping highway turns), and a slight difference in overall effort/assist. Is it extreme? No. However perceivable, especially with this issue regarding the shudder feedback.

Here's some others who feel the same way: (including Sam Strano)
http://forums.themustangsource.com/f800/sport-mode-490283/

I agree there's little/no documentation, but there's a definite feel change in steering when in sport and advancetrack off modes (note I'm not mentioning traction, throttle commanded/actual, braking or other factors). I can even discern it sitting parked.

what shuddering could a throttle/abs based system cover up exactly? Especially one that comes in with speed and steering input?

captdistraction said:

Probably can say it all you'd care to, I'm certain of my findings.

we can agree to disagree then. I can perceive a noteable difference in feedback (especially with the shuddering on sweeping highway turns), and a slight difference in overall effort/assist. Is it extreme? No. However perceivable, especially with this issue regarding the shudder feedback.

Here's some others who feel the same way: (including Sam Strano)
http://forums.themustangsource.com/f800/sport-mode-490283/

I agree there's little/no documentation, but there's a definite feel change in steering when in sport and advancetrack off modes (note I'm not mentioning traction, throttle commanded/actual, braking or other factors). I can even discern it sitting parked.

what shuddering could a throttle/abs based system cover up exactly? Especially one that comes in with speed and steering input?

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It wouldn't. My point is that if your problem gets worse in Sport mode, it is not a problem with EPAS, but with ESC. Again, show me actual documentation that cannot be explained by the placebo effect.

I guess in the end it doesn't matter. We will get an answer for the shutter when Vorshlag's car gets a new rack in it.

applesauce683 said:

I guess in the end it doesn't matter. We will get an answer for the shutter when Vorshlag's car gets a new rack in it.

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Well this is true.

In the spirit of cooperation, I'm going to put my car in sport mode for the entire 30-mile commute home and see if I notice a difference. Again.

Sky Render said:

Well this is true.

In the spirit of cooperation, I'm going to put my car in sport mode for the entire 30-mile commute home and see if I notice a difference. Again.

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It wouldn't surprise me at all if later production date 2011's had the feature but we won't have a definite answer, short of a Ford engineer responding.

applesauce683 said:

Definitely interesting. Possibly later build dates had the feature?

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My build date is 10/10.

Never experienced any shudder or feedback in any form of driving in any Advanced Trac mode.

I have factory brembo wheels with larger 275/40/19 tires. Front camber is set a -1.5 degrees, alignment done by the guy at my MB dealer who also does Porsche, Aston Martin, all exotics that come in as trade-ins, basically as good as they get. Toe and caster set within factory specs.

I should note there was a PCM update for other issues and some have noticed improvements to throttle response and power. Perhaps this software update also incorperated itself into other control units and changed how the EPAS and ESC function with each other. Anyone have this update done? I have not FWIW.

Sky Render said:

It wouldn't. My point is that if your problem gets worse in Sport mode, it is not a problem with EPAS, but with ESC. Again, show me actual documentation that cannot be explained by the placebo effect.

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How can esc cause the issues people are talking about in this thread (and on other boards, while searching I found my own threads from early 2011 asking about this)? Only way to induce a steering feel like that would be to pulse abs on the front brakes, however when I feel the shudder, there is no associated drag on the car. Disabling sport mode and returning to normal while the shudder is in play causes it to fade over a period of roughly two seconds. Balance is verified on the wheels (I also had the luxury of testing multiple sets), and it also disappears when steering is centered.

To make sure all on same page, I'm talking about scenarios on highways, in lawful use of the car (not any type of situation where the car would be engaging TC or ESC systems). Static throttle, 70mph, 10* steering input held static and then released to center. edit: for your commute test, find similar conditions and flip between the modes and see for yourself)

Its an EPAS issue, without doubt. I've felt it since day one in my car (brembo equipped GT). I'm wholly certain its not a placebo effect, but regardless of where we stand on that I can't find a plausible situation where the shuddering could be caused by the ESC.

I'm not saying the shuddering is a placebo effect; I'm saying increased steering feel in sport mode is a placebo effect.

I have the shudder in my 11 as well. Had it on stock 18s with stock suspension and now with my 19s and steeda ultralights.

Sub'd

If you are reading this, and have experienced this issue, please post up.

I will let you know what I am able to find out.