EPAS Terrible Shudder

[aequitas4]

Sorry for the delay. As I said before my shudder was not nearly as bad as some of the videos but it definitely drove me crazy. As of today my steering shudder is still gone... almost at 190k now. There were a few other items I found helped the situation.

1. I removed the junky rotor retaining rings on the hubs as some people claimed they could cause balance issues. (I think this helped slightly but it was hard to tell).

2. I replaced my front control arm and bushing assemblies with new stock ford ones. (I noticed NO IMPROVEMENT in the shudder from this) even though my original Ford stock bushings were demolished. Handling is way better though

3. I adjusted my hood alignment and the hood height bump stops. At high speeds the hood bouncing in the wind actually did contribute to my steering wheel shaking (I know it sounds crazy but it HELPED A LOT)

4. The item I referenced about using the ForScan app was then used when I found calibration faults:
Quoted from my message above: "I got a bluetooth obd2 adapter with the hs/ms switch and downloaded the forscan app for my android. When I scanned the steering module it found some calibration faults that weren't throwing CEL's. I simply reset the steering, abs, and restraint modules using the FORSCAN app and restarted the car."

5. The final item was another tire balance and alignment after the install of the new Ford control arms.

I would like to make sure I clarify that I never had aftermarket bushings on my front control arms. My stock ones were definitely shot when this started but replacing those did not improve my shudder.

Since then the car has been riding smooth with no shudder in the steering wheel whatsoever.

 

[Norm Peterson]

Glad to hear you got it fixed . . .


Now what does "hs/ms" stand for? I can't even begin to guess.


Norm

 

[aequitas4]

The hs/ms switch physically switches between two wires in the obd2 adapter to run in either the hs or ms mode to make sure you can access all of the vehicle modules. Its the two separate CAN bus systems. more info here:

How to add HS/MS CAN Switch to ELM327 OBD2 scanner | OBDII365.com Official Blog

All of the modules in the mustang are either on the HS or the MS bus. you have to physically flip the switch for the software to access each set.

 

[Norm Peterson]

Can-bus speeds???


Norm

 

[aequitas4]

That sounds right. High speed / medium speed ?

 

[Juice]

Yes high speed can/medium speed can bus.

 

[LarryJM]

The hs/ms switch physically switches between two wires in the obd2 adapter to run in either the hs or ms mode to make sure you can access all of the vehicle modules. Its the two separate CAN bus systems. more info here:

How to add HS/MS CAN Switch to ELM327 OBD2 scanner | OBDII365.com Official Blog

All of the modules in the mustang are either on the HS or the MS bus. you have to physically flip the switch for the software to access each set.

I do think they sell one without a switch that does it all. It's about $60 on Amazon.

 

[summerfield2011gt]

Hey so I read every post on this thread. And want to say I have an ACTUAL solution using forscan.

I just had my front end rebuilt including LCAs. Shocker, my early build 2011 GT did not like that. Wicked shuddering. The solution after hours of playing around with forscan ended up being simple.

Go into the PSCM programming as built section using the forscan extended license and appropriate elm canbus to USB adapter.

You'll be presented with only 1 editable 4 digit box. Set the first 2 digits to 06. Then hit write. Forscan will automatically calculate the correct final digits during the writing phase.

That's it. It appears to disable the epas system altogether with zero warnings on the dash or unwanted behavior. I tried all the known values and none of them made a real difference. But 06 stopped all shudder under all circumstances.

No need to buy a new steering rack. No need to beg Ford to reflash when they won't. Just a free program, a $60 adapter, and 3 minutes of your time.

Hope this helps someone in the future!

 

[summerfield2011gt]

Yes, my customers have different symptoms dependent upon which set they use, and they are balanced properly.

The 4-5 different Ford part #'s are based on wheel/tire size-combo from the factory.....so it surely has something to do with it.

EG: the EPAS rack on a Mustang with 18" wheels has a different part number than a Mustang with 19" wheels.

See my recent post. I found a forscan solution.

 

[summerfield2011gt]

The M-3200-EPAS rack is finally back in stock. This is merely a stock 2011-up rack reprogrammed by Ford Racing to turn off all of the loopy programming.

This single swap will fix any and all steering shudder caused poor electronics programming and/or major suspension mods.

Works perfectly on the street, autocross or track. Took one of the largest (and only) complaints I had with this chassis and completely removed the issue. I was 100% satisfied.

I found a forscan solution. See my recent post. Performed it on my own vehicle before posting the details here.

 

[summerfield2011gt]

While trying to find a solution to the issue for Terry I've spoken to the actual Ford engineer that does this and they refuse to reprogram used racks and will only sell the programming with a new rack. I don't know if it's because the ECU cannot be re-flashed once it's been programmed, or other issues. But I doubt it's strictly because of commerce. They were very sympathetic every time I called and tried to find other workarounds.

If someone has an inexpensive aftermarket solution I'd like to hear about it.

I did find a solution using forscan. Tried experimenting on my 11 and using 06 as the first 2 digits in the PSCM seems to disable the EPAS behaviors. While retaining actual power steering. Forscan auto checksum calculation will determine the last 2 digits for you when you write.