Steering holds a left turn?

[Jay-rod427]

I believe there is a Ford procedure regarding the steering input sensor to recalibrate it.

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[FISHTAIL]

My Z4 does that with its electric power steering, it's way out of warranty though so I just kind of deal with it.

It also feels like it has "steps" in the gearing just off center, but nowhere else. Annoying as all F.

Well at least it's not just me. Funny thing is, my 2011 never did this, nor did my ST, and my wifes Explorer is fine as well (and she's at just under 170k miles).

In my case, I'm wondering if it's not the crown correction doing the wrong thing...we'll see what they find. I told them that they were welcome to turn that feature off though.

 

[FISHTAIL]

I believe there is a Ford procedure regarding the steering input sensor to recalibrate it.

Yes there is actually. I have a friend who's a ford tech, and he brought his IDS home one day so we could try that, but his battery died on us (he forgot to charge his computer). If they can do that, great. I haven't heard one way or the other though..we are approaching the end of day 2 and I haven't heard word one back from the dealer.

 

[FISHTAIL]

Thread update;

Finally heard back from the dealership. They said everything is within spec and the car is driving normally. Apparently they are unable to reproduce the behavior, though I'm not sure what the tech has tried since all you have to do is take a gradual left turn at 40+ and let go...the car will follow the corner.

They are going to check one more time and call me back tomorrow, but I'm pretty sure I'm on my own with this one. Does anyone know if you can disable the crown assist in the EPAS? Because it really seems like that's what the issue is to me, and would explain why it's only left turns.

 

[FISHTAIL]

So...I just did some reading that I should have done before I ever brought the car in. I just ran across a thread over on one of the F150 forums, and a post from a guy that claims to have helped work on the EPAS system design.

Assuming he wasn't making stuff up (this is the internet afterall), his post was interesting and it makes lots of sense as to why my issue could be happening.

So like I posted above, the holding a turn issue is way worse on the comfort steering setting. And here is my theory why (we'll see if the dealer has any luck and can corroborate this):

According to the F150 forum, the EPAS system has a torque sensor on the steering input shaft that it uses to determine direction and force being applied to the wheel. From that, it figures out how much assist to apply. The crown assist/cross wind assist, works by seeing that you've continued to apply a steady amount of pressure in a particular direction for x amount of time then ups the assistance to make that job easier on you.

After reading that, I realized that part of what I was doing to get a car to stay in a corner was holding it in the corner myself for a few seconds before letting go. So what I think is happening is the car can't see me letting go...that there is a dead spot in that torque sensor, and continues to apply assist even though I'm not turning the wheel anymore. And since the corner is gentle, the assist is enough for the car to hold the turn itself.

This explains why it has to be gradual turns. It also explains why turning in sharper, or turning out a little, causes the car to straighten up. It also explains why it's easier to do it on the comfort setting...there is more assist being applied in the first place, so it will hold a slightly sharper corner.

Now, I don't know that's the problem obviously, but it sure seems to fit. I emailed my service writer with the additional info, including that the tech needs to find a long gradual turn, and hold it himself for a few before letting go, to get the behavior to materialize. The car will pass the "flick test".

As hard as I tried to vocalize this issue when I dropped the car off, I didn't even realize I'd been holding the wheel for a few seconds myself until I read that thread about the EPAS.

Anyway..I'll update again after I hear back from the dealership, and I hope this info is helpful to someone somewhere along the line.

 

[Norm Peterson]

That it only happens in left turns still sounds like the steering angle sensor is somehow involved.

If the car has been aligned, was the SAS reset?

Did you ever hit a bad bump or pothole that could have knocked the toe off on one wheel only?


Norm

 

[FISHTAIL]

That it only happens in left turns still sounds like the steering angle sensor is somehow involved.

If the car has been aligned, was the SAS reset?

Did you ever hit a bad bump or pothole that could have knocked the toe off on one wheel only?


Norm

Never been aligned, or hit any bad potholes that I know of. From what the dealership said, everything is in spec.

 

[FISHTAIL]

Heard back from the dealership again today. They claim it's normal, and everything is in spec. I find that a little hard to believe, but I'm pretty sure I'm SOL with getting it fixed there.

I'll try another local dealer again in a few weeks when I get some time, and take them for a ride to show them, but I suspect this one is going to be out of pocket.

 

[FISHTAIL]

Picked the car up, and first turn I take I can let go of the wheel and the car will follow the turn all the way through, and cross the line at the end...so I have no idea why they couldn't reproduce it. I might take some time off tomorrow afternoon and run over to another local dealership to grab a Tech and take them for a ride.

 

[wildcatgoal]

Is this not the standard bad rack?

 

[FISHTAIL]

Is this not the standard bad rack?

Probably, but they said it was fine and didn't fix anything.

 

[FISHTAIL]

So update from today;

Although it was acting up on the way home, it proceeded to be fine for the next few days. Cue today...on my way to get my daughter the car starts acting as bad as it ever has, so I drive straight to the local dealership, leave the car running, and run in to grab a tech. The head tech comes out with me, gets in the car, and we go for a ride. And what do you know...the damn thing quit doing it. *sigh*.

Guess I'll just hang tight until it gets worse so it's not such a pain to reproduce. The tech at the dealer did take the time to go through Oasis with me looking for similar issues. The closest one we found was a guy who had a similar issue due to a bad rear tire, but his wasn't behaving exactly the same way mine is. Still, I swapped the rear tires for the hell of it.

 

[wildcatgoal]

Go under there and check the electrical connections to the rack.

 

[FISHTAIL]

Go under there and check the electrical connections to the rack.

I doubt that's the issue, but it's not a bad idea. I need to change the oil so I'll have a look when I'm under there.

 

[wildcatgoal]

It's not hard. I've fixed a few things unplugging and replugging plus before! Haha.

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