I talked to my dealer about a minor steering problem a few weeks ago and didn't get any useful info, so I was going to write about it here. But yesterday I went back to the dealer and talked to the service manager and he said it was most likely just the PDC (Pull Drift Compensation) system and that what I was noticing was when it turned itself off after a ten-second timeout while driving around a curve.

The system is described at https://www.f150forum.com/attachment...-pull-drif.pdf. It tells me indirectly that both the PDC and the Lane Departure Warning systems might cause unexpected sensations in the steering wheel. In my case, the problem is NOT coming from the Lane Departure Warning system.

What disturbs me is that I had the truck for over a year before ever feeling the PDC, and now I feel it daily. The PDC description says it should fade out over ten seconds, but I think I'm feeling an abrupt turn off with a resumption of higher steering effort. Is this something anyone has encountered, and does it require a PDC repair or recalibration?

 

yep! There is an SSM and Update to the LKA calibration to correct it. Do this to confirm, on a straight section, doing about 55, give a sharp tug on the wheel, recenter it, and see if it now pulls in that direction, and do it the other way and see if it follows. If it does, then the LKA update should fix it. I have a thread on this around here somewhere with the SSM information.

 

Was there a resolution to this? Was it anything like what I am describing in the link below? What year F150?

https://www.f150forum.com/f38/ongoin...sation-415461/

 

EMSbyDay, I don't think it is the same problem. Mine was much more subtle than yours, and it seemed to resolve itself. The dealer said there was a software update to the pull drift compensation problem but I never had it installed (yet).

I'm also fairly sure the electronic steering that has pull drift compensation didn't come in until 2012 or later, so I don't think that could be the problem on a 2011. But some Ford models may have had it earlier.

My truck is a 2016.

 

SbyDay, I don't think it is the same problem. Mine was much more subtle than yours, and it seemed to resolve itself. The dealer said there was a software update to the pull drift compensation problem but I never had it installed (yet).

I'm also fairly sure the electronic steering that has pull drift compensation didn't come in until 2012 or later, so I don't think that could be the problem on a 2011. But some Ford models may have had it earlier.

My truck is a 2016.

 

EPAS and pull drift compensation started part way through the 2011 model year I believe. Mine apparently has both.

Dealer quoted me $2500CAD to replace the electronic steering gear. It's my and more importantly my family's safety at stake so I told them to go ahead an order in the part.

Oddly enough, it hasn't been an issue for almost 2 weeks...

 

So you had an early electronic steering, and I had an early Sync3 system, which is where I had my problems. The difference is that your problem didn't occur under warranty, and of course yours is a safety issue, while mine was not.

 

Is this also what causes some of these trucks to wander so much? Mine does not like to steer straight. I mentioned it to the dealership when there was an ongoing issue with my lane departure assist (it jerks the wheel if you hit the line while going around a curve) and they said it's normal. They also said it's common for the truck to feel like it's wandering with the feature enabled. I was highly skeptical that this was normal but I had to pick and choose what I wanted the dealership to go after since I have several other issues. Nevertheless, it still wanders whether lane keeping is enabled or not. If there's an SSM for this or TSB, that would be awesome. I haven't been able to find one that matches my build date.

 

The way PDC works is it measures the amount of torque applied to the steering wheel over a given amount of time and then applies a corrective force to ease the amount of input required to keep the vehicle straight. So if you have a high crown road that causes a right pull, and you are forcing the wheel left to stay straight, after about 14 seconds or so the EPAS will apply a little left force so the steering lightens up. If you have a strong cross wind that pushes the vehicle in one direction where you are applying corrective force, it will detect that and apply force to ease the steering. When you are no longer being pushed, or the road flattens out, you will find that you are applying opposite torque to stay straight until the EPAS PDC detects and readjusts the correction.

What I have experienced is that going over a rough road, the system is constantly applying corrections and causing the truck to pull left or right, and sometimes with a lot more force than required causing a firm pull either left or right. There is one section of road that I know it will pull hard on, and it is not in just one direction as it can be either right, or left at the same place on any given day. If I am not paying full attention, I just might have a head on as it pulls that fast and the steering wheel does not jerk, nor pull, but the truck moves as if it did. I have to correct quickly when it happens. I first noticed this strange behavior while towing my TT home from Nebraska, thought the Ford corrected it, but now it is back even worse than before.

I should mention that it does it with or without LKA engaged.

 

I set my Lane Departure Warning to minimum sensitivity so all I get is a very slight vibration in the wheel, and no compensation. I live in the hills where many drivers will cross solid lines on winding roads regularly to smooth them out when there is no oncoming traffic, so the default settings when I got the truck were awful for me on the way home from the dealer.

As for the truck wandering, I would not describe the steering issue I had as wandering. It was just an unexpected sudden change in steering effort a few times. The problem did not recur, but the dealer did have a TSM update for pull drift compensation that I never got around to having installed. If the problem recurs I will definitely have the update installed. I noticed it mostly on windy days on downhill curves, and I haven't experienced those recently.