I have a 2012 Super Duty, and of course it comes with traction control. Since it was new, I have always wondered if the traction control works on just the rear wheels, or if it would also work on the front wheels as well when 4x4 is engaged. Its easy to see the traction control working on the rear wheels during the winter. There were times, however, I felt it was also working on the front, when spinning in very deep snow this past winter. The owners manual does not specifically state one way or another.

If it indeed works on the front wheels as well, the next question I would have is how the front works: does the 4x4 lever or control **** act as a 'switch' which turns on or off the traction control system to the front when 4x4 is engaged or disengaged? Or, is the system active on the front and rear wheels at all times, checking wheel spin on one wheel vs. the other wheel on the same axle...and of course serious wheel speed differential would only occur on the front if 4x4 was engaged? (I suspect maybe this is how it would work).

I'm also guessing (again, if the vehicle actually has this function) that the threshold for front-wheel traction control activation is higher than for the rear wheels due to steering causing more wheel speed variation anyway.

Finally, one question about the 'traction control off' switch on the right side of the dash. My initial impression was that pressing the switch shut down traction control by left stability control on. However, I tried to spin the tires on pavement the other day, and although it would 'chirp' a couple of times, there was no doubt traction control was still applying the brakes. Or maybe to disable traction control completely I need to press and hold the switch? (That might be answered in the book).

Overall, I think the traction control system is relatively helpful especially in snowy conditions. I know some people have a lot of criticism for traction systems in general, but I think it works relatively well. Therefore, I'm curious as to whether Ford spent the extra couple of bucks on programming to allow the fronts to work, or just the rears. Anybody know for sure?

 

Yea press and hold the button to turn it off, but even then I'm not sure it's all the way off. With some of the tuners I think you can completely turn it off.

 

From our experience with Fords the TCS always use all four wheels, applying the brakes where necessary. We don't know if you can isolate it to just the front or rear wheels but doubt you could do so, as there would be no advantages whatsoever.

 

OK, I realize the "Stability Control" portion of the system operates on all 4 wheels at all times. That's what's supposed to keep you from rolling over or understeering into the lane of oncoming traffic, or spinning out.

But I'm talking about the "Traction Control" portion of the system. That's the part which tries to prevent just one wheel from spinning on a powered axle with an open differential, and get you moving again. Lots of people get confused on this distinction, especially as manufacturers often market both systems under one name, such as Ford's "Advance Trac."

Clearly, the traction control is active on a pickup's rear wheels at all times, because of course a pickup's rear axle is powered at all times. Therefore, the traction control system for the rear wheels is always effective. However, if the truck is not in 4WD, the front axle is not powered and no 'traction control' can be used on that axle to aid in the truck's forward progress. But when the truck is in 4WD mode, the front axle is powered, and now a traction control system would be effective in aiding forward progress, in addition to the system working on the rear wheels.

So my question is whether or not the capability is there, and if so, how does the front wheel traction control come in to play? The hardware is there, since I believe all the Ford trucks have 4-wheel ABS. It would just be the software programming. If the truck does have this capability, is the front axle traction function entirely turned off by being in 2WD mode? Or does the system constantly monitor each front wheel for wheelspin against its opposite, just like in the rear?

There are a couple of considerations as to why a truck might NOT have this ability...

1. There are significant programming algorithms which would need to be included into the ECU's at additional cost per unit (would Ford really use a separate ABS ECU for 2WD models which will never need front traction control? Or would they be willing to run the same ABS ECU in the 2WD trucks as the 4x4 trucks, with a more expensive but useless feature programmed into it?)

2. Perhaps more compellingly, a traction control system is very hard on drivetrain components. Rapidly pulsing the brakes on a heavy wheel which is spinning fast 'shocks' the hub, axle joint (or CV joint, on F-150's), axle half-shaft, and differential gears during each braking pulse. This would mean the front drivetrain hardware would need to be heavy-duty enough to accommodate repeated operation over thousands of miles. Some of you might be laughing, thinking 'sure, a full-size Ford truck can't handle the "strain" of a traction control system.' Well, for example, Land Rover was perhaps the first adopter of traction control systems on a 4WD SUV (starting in 1992) and all of their vehicles which came with the system only included traction control on the rear wheels all the way up until 1999. In 1999, they introduced 4-wheel traction control, and the reason was that previously the front axle half shafts and front differentials were not strong enough to withstand the systems operation. Yet this was in a very heavy SUV designed for day in, day out pounding in off-road severe environments. In the case of the current Super Duty, I suspect there is plenty of 'beef' in the front end drivetrain to accommodate traction control, but in the F-150, I wonder.

I wish I knew conclusively. I guess you could jack up opposite wheels on the front and rear, then put the truck in gear in 4WD and see what happens...but even the rear wheel traction control alone would probably push the truck off the jacks.

 

In my other 4WD vehicles, Traction Control (not stability control or ABS) is turned off as soon as the front axle was engaged.

I'm interested in knowing how this works with these new trucks...

 

Awesome truck you've got on order, bigfoot. You'll love it. One thing I know for sure is that stability (and I believe traction control as well) turn off when you engage low range...probably too much torque to be hitting with the brakes for the driveline to handle repeatedly. But, traction control is definitely still enabled in 4x4 High, just whether or not it operates on the front is what I'm curious about. Another thing to note is that while the rear e-locker (if equipped) cuts out above 30mph or whatever in 2WD or 4WD high, it stays locked at any speed in 4-Low (not that you can go all that fast in low). I'm pretty sure traction control operates on all four wheels when in 4WD high and you're spinning all the wheels based upon my experience in deep snow last winter. Another question would be, does the front traction control cut out in 4x4 with the rear diff locked? Again, I think not.

 

Traction control can be as simple as reducing engine power to reduce power going to the wheels - be it 2wd or 4wd.

Stability control can be as simple as sensing vehicle yaw and applying slight braking to one/both rear wheels.

My wifes '04 explorer has auto 4wd (no 2wd only mode). It senses rear wheel tire spin and engages the front axle 'instantly' works great at right hand corners in the rain.

In some vehicles, engaging the parking brake one clic, when the ebrake light comes on disables abs and/or traction/stability control.

Likewise, 4wd low, can also disable certain capabilties as well.

edit. Trailer sway control is similar, in certain vehicles, it can apply brake(s) or reduce power, and sometimes apply trailer brakes as well.

Naturally disclosing too much helps competitors and ford does like the driver have too much info. Aka idiot gauges with no scale/marking for actual temp/pressure.


Sent from my Sprint PC36100 using IB AutoGroup

 

From page 280 of the owners manual, 4th printing:

3. Engaging 4WD Low locked automatically disables RSC, ESC and TSC.

Otherwise, it is on unless the driver deliberately disables TSC.

 

If you have a DRW 350, then yes, traction control is only based upon reducing engine power when wheel slip is detected.

All the SRW Super Duty's have brake and throttle based traction control. Obviously, only the brake portion of the system "possibly" acting on the front wheels is of concern here.

Stability control requires more than just a yaw sensor, it would require at minimum the yaw sensor and a steering angle sensor, but usually any stability control system also takes input from the throttle position switch, the brake pressure switch, and sometimes a rotational sensor.

Not sure what Ford is trying to "hide" from anyone. 4-wheel traction control has been around for at least 15 years, and any competitor can buy any Ford and reverse engineer it. I would agree that manufacturers don't want the owner / driver to know too much...if they did, maybe the dealer bull artists wouldn't be so successful at pulling dollars out of owner's wallets.