EPAS Terrible Shudder

Sam Strano

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I have to admit I find some humor in all of this. My car does it too.... but then so did my 2007 which doesn't have the same system as the 2011.

It tends to happen on cars with negative camber, and usually some toe-out too. In fact a toe change last week helped a lot.. now it's back after about 700 miles (granted I run a lot of negative camber).
 

Vorshlag-Fair

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Has anyone had any shimmy problems after installing aftermarket wheels? I really have not read about any problems.
Our 2011 Brembo GT does it with the stock 19x9" wheels and tires plus any of the other 18" wheels we have (two sets of 18x9" + 18x10"). We didn't experience any of this before the car was lowered, however. That may or may not be relevant.

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I recall reading that the Ford EPAS can make adjustments for out of balance wheels. This makes me think it may be a malfunction of that system/ECM logic. Dumb question I'm sure but with the significantly smaller tires your running is the revs per mile properly set? I would assume that system would have to use wheel speed one way or another.
Again, we've had it happen on the stock tires (255/40/19), and several other non-stock sizes we have run on the car (275/35/18, 265/40/18 & 265/35/18). So far it looks like tire height makes zero difference - in the same corners it will shudder violently.

We have an SCT tuner with custom programming that can compensate speedometer for various tires sizes. And before you ask, no, the SCT tuner/software does not alter anything on the EPAS system, that we know of. The steering shudder was there when the engine calibrations were bone stock - before we added the tuner/CAI - too.

I'll report back after we have Ford flash in the new software for the EPAS (the TSB).

Thanks,
 

Twinscrewgt

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I have 20" wheels all the way around. Mine shudders around 70-80mph. I just figured it was from lowering it and neg camber
 

Digital_Synapse

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70-80 going straight? or taking a sweeping curve?

I've never noticed anything shaking and I've taken the current set of wheels to 140. It was very quick though, wasn't a slow climb, so I didnt stay in the 70-80 range long.
 

DCS

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We didn't experience any of this before the car was lowered, however. That may or may not be relevant.

I'm not sure how it couldn't be relevant. Remember the joke "Doctor, it hurts when I do this...!"?

Don't do that.
 

Sky Render

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I have to admit I find some humor in all of this. My car does it too.... but then so did my 2007 which doesn't have the same system as the 2011.

It tends to happen on cars with negative camber, and usually some toe-out too. In fact a toe change last week helped a lot.. now it's back after about 700 miles (granted I run a lot of negative camber).

Did your car do this when stock?

I have not experienced this problem, but I'm still running stock tires and suspension.

Sent from my DROID2 Global using tapa-whatzit-thing
 

KJGT

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May want to try disconnecting the epas and see what happens, I'm sure the dash will light up like a christmas tree but that would tell you right away if it was something with the EPAS logic.
 

SeVeReDiStOrTiOn

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I have to admit I find some humor in all of this. My car does it too.... but then so did my 2007 which doesn't have the same system as the 2011.

It tends to happen on cars with negative camber, and usually some toe-out too. In fact a toe change last week helped a lot.. now it's back after about 700 miles (granted I run a lot of negative camber).

I was just about to say I don't think it's EPAS related my 05 does this as well...and i've read many similar threads for 05-09 owners.
 
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What ever ended up being the outcome of this? My 2011 started doing it about 3 weeks ago. Sometimes when you hit a bump the steering wheel starts shaking uncontrollably and either i have to turn the car off or slow down to get it to stop. My cars been lowered since the 2nd day i had it and has had the welds on it almost as long, its does it with the factory wheels to. I have 32k miles on my car and it never did it before. I installed the Bmr k-member about 2 months ago, so i dont know if that had something to do with it.
 

Grimace427

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Last I read on their forum was they were waiting for Ford Racing to release an updated version. The factory steering rack has been on backorder for months. Seems they will be available June 23rd(today).

05/03/12
"We have to have the updated programming for the steering rack before any of these events, as I'm tired of seeing the same nagging computer errors and steering wheel feedback. Now that we're confident this programming is SCCA legal I'm going to get it done. We will be pulling the rack out of the car this week to send it to Ford Racing, as the replacement $1000+ 2011 GT racks is on national back-order. Apparently there's a 3-4 month build date window where all of the early 2011 GTs are having similar "issues". Ford is not doing a recall yet, but probably will "eventually". If you are seeing this type of steering shudder CALL YOUR FORD DEALER and demand a recall/TSB. If you don't want to wait, call Ford Racing in Detroit. All of the World Challenge and GRAND AM Mustang's run this update programming, and it supposedly fixes the steering feedback loop shudder and related Traction Control system faults. We'll find out and report back soon!"

05/23/12
"The one problem that was missing was... the traction control faults and steering feedback shudder. WTF? This is a mystery but I have noticed that the more wheel spin we see the more problematic the steering is and the more faults we trigger. With 345mm rear A6s and a fresh LSD out back there was dramatically less wheel spin. This is good, because both the OEM replacement and the FRPP race re-programmed steering racks (M-3200-EPAS, $1249) are on national back-order until June 23rd. We found one in the country after calling dozens of places, and they were saving it as a spare for their GRAND AM race team. Wouldn't sell it to us for any amount of money. So... we cross our fingers and hope this steering rack and traction control fault issues take a hiatus. :/"
 

BMR Tech

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This has been happening for some time now.

I am trying to dig into this issue, as it appears to be pretty common among my customers.

There are 3-4 different part #'s for EPAS racks. Each part # is dedicated to wheel size. There is a version for each combo, 17" / 18" / 19" and 19"F-20"R.

Our 2011 GT has only had this occur a few times, and the 2011 GT500 that we had in our shop the other day, has this same issue occur.

MY personal opinion is that it is a feedback issue, where the EPAS system is overcompensating. Basically, on a long sweeping turn, it is applying more power...or possibly even pulsing....when the driver is holding the wheel in a select position, causing a resistance issue.

I am hoping that the issue is not amplified by using higher durometer/stiffer front a-arm bushings.
 

01bluesnake

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Been getting a light amount of shudder at highway speeds as well intermittently. Car came with 18"s originally, installed 19" Brembo wheel setup and lowered the car, so im sure its off from the original programming.
 

Sky Render

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If there are different part numbers for different wheel sizes, could this be caused by running different-sized wheels than stock? I have aftermarket wheels, but they are still 18", which was my stock size. I don't think I've ever experienced this issue.
 

applesauce683

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I developed this problem after installing the BMR K-member and A-arms. Not a knock against the products, they work great and would recommend them, it is definitely EPAS related. I only encounter this problem with the EPAS in sport mode. It never happened before with my aftermarket 18" wheels from my OEM 19" wheels, so I don't really think it is related to wheel size. Really wish Ford would remedy this.
 

RazorbackMustang

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Now that I think about it, I have briefly noticed this, but also in sport mode only. It's a very light shudder and only under hard braking. I was road coursing Saturday and noticed it then.
 

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