Crazy Surging

[Grumpy2]

Who puts children in the front seat?

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[Bespectacled Ape]

Who puts children in the front seat?

Who blames parents for a simple software fix?

 

[Henry Ford]

And don't get me wrong, this is a totally a "beast" of a truck and I am very happy with it, but no I am not going to trust the programming. Case in point, I am glad the latest update fixed one our window issue, but I am 100% positive the "feature" of automatically rolling the window all the way up will result in the death of many children. All it takes is sticking a head out the window and pulling up on the button. The force required to stop the window is more than enough to snap a little spine or fracture a hyoid. All for convenience?

Automatic windows have been around for a long time. Do you really think there isn't a fail-safe engineered into them?

 

[Bespectacled Ape]

FYI the surging is not the same period as any porpoising. I can deal with that. Bush league. This is different. Like two overlapping sine waves of different frequency, perhaps even in harmonic resonance with chain length. Do you follow me?

PS All the way through this, I am not sure what is throwing the truck back and forth (surging). Difficult to see how the chains could allow the surging when the bars are tied to the hitch. What is providing the slop need to allow the surge? Adjustments and weight balance will help porpoising and steering control, but again folks, that is not the problem. It is surging, hence, probably software.

 

[Grumpy2]

One last attempt ...

You are towing a 10,000lbs load with a 7,000lbs truck. To control this setup you need to lock them tightly together, other wise the 10k load will control.

The only weight distribution hitch I have experience with is the following.

I had to carry a 4' long pipe to engage the 1200 lbs (capacity) bars. Once you have properly setup the hitch, and the sway bars you will have a solid system and the truck will feel like your driving a locomotive.

 

[TaxmanHog]

It is surging, hence, probably software.

Over the years, I've read of other members overloading or putting it close to capacity, none reported a surging situation that I recall.

Did your Lightning come equipped onboard scale? (some builds had it deleted due to lack of supplies).

I'm curious if there is an erratic output from the weight sensor, that's feeding the algorithm bad data and leading to a surging sensation.

Is the readout stable, you might see slight variations, sometimes the scale reset fixes that.

If you have it, go to the scale menu, reset it to baseline [EMPTY], you can calibrate the expected passenger, cabin and bed cargo loads to offset the available capacity for tongue weight.

Attach the trailer, review the tongue loads impact on the scale, with & without the weight distribution hitch supporting the load, is the scale indicating overload conditions?

Adjust your WDH & ride height to it's optimum settings to get the tongue weight into spec.

 

[Henry Ford]

New guy: "I've come to the most extensive knowledge base of Lightnings outside of Dearborn because I have a problem and would appreciate help."

Everyone: "The fix is probably this."

New guy: "I don't like that answer and you are all rubes."

Everyone: ?

 

[SpaceEVDriver]

You claim to be a scientist but you're dismissing the several peers-review you asked for. You've settled on a hypothesis and are ignoring the peers who are telling you that hypothesis is unlikely to be correct. You are hauling 8,200 kg of mass at 88 kph (2.5 million Joules of kinetic energy) down a roadway with other, innocent, people alongside you. You need to let go of the ego.

Before blaming Ford, you should allow for the probability that you're loading and hitching incorrectly.

More importantly, if the Lightning is unsafe to be using as a tow vehicle because of something you cannot fix (Ford's software), then you should park the trailer until you can get ahold of and use a properly-functioning tow vehicle. Otherwise you're putting others in danger and that's just not cool.

In the meantime, why not methodically and properly do all of the things you can to fix or eliminate other possible problems that are within your control?

1. Start over. First, read the owner's manual towing section, as well as all the precautions (cruise control, lane keep assist, 1PD drive, etc., etc., etc.) throughout the manual. Also read the towing-specific manual. The link can be found in the owner's manual.
2. Check that the trailer suspension is in good condition, that the trailer tires are in good condition, and that the trailer frame is in good condition. Surging as you described, whatever the cause, can damage the trailer, and you should double-check all of the parts of the trailer that might have been damaged. If any damage has occurred, you should not be towing the trailer until it is repaired.
3. Check that the truck's hitch is still properly attached to the vehicle. Surging like you described, regardless of the cause, can damage the truck's hitch and possibly the frame. If any damage has occurred, the truck is no longer safe to use as a tow vehicle until it is repaired.
4. Next make sure you have properly distributed the trailer weight so it's not too heavy behind the axles and not too heavy on the tongue. The tongue weight should be not more the maximum tongue weight of the truck (1000 pounds with a WDH--include the WDH weight in your tongue weight calculation) and not less than 10% of the trailer weight. With a 10,000 pound trailer that's 1000 pounds. If you're really towing 10,000 pounds, you have a very, very narrow band to get the tongue weight right, which means proper WDH installation, especially ball height is absolutely critical.
5. Double-check your truck tire pressure. It should not be 39 PSI as recommended by Ford for normal driving. Instead the tires should be properly inflated to manage the load you've put on the vehicle.
6. Double-check your trailer tire pressures.
7. Find a level—truly level—surface and level the trailer. Don't do this by eyeball, use a proper instrument. Measure the rake of the truck while it's not connected to the trailer—you will want the final rake when the WDH is engaged to be close to the rake without a load.
8. Set the hitch height according to Ford's and the hitch manufacturer's instructions. I cannot believe you allowed some random dude to assert that it should be just high enough not to touch the tailgate--that's a moronic way of setting ball height. I've been towing for 40 years and have never heard something as stupid as that. Proper ball height is dependent on the very specific truck+trailer+trailer load combination. The fact that you allowed this is why I believe you're making assumptions and assertions without evidence and that your troubles likely stem from an improperly loaded trailer and an improperly set hitch height.
9. Use the hitch manufacturer's instructions to properly set the tension on the WDH chains. It's not always simply "as tight as possible."
10. Calibrate the brake controller's gain (the instructions are, in fact, in the Ford owner's manual).
11. If doing all of this correctly doesn't fix the problem, then you might have an argument that there's something wrong with the truck. Try driving without any sort of driver assist engaged. No cruise control, no lane keep assist, 1pd off, etc. If there's no cruise control engaged, the truck will not engage the accelerator. If there's no braking assist on, the truck will not engage the brakes without a system/safety warning. If these things are happening when you have no software engaged, then maybe it really is a software issue. In which case it's time to park and find a different tow vehicle until you can get that fixed.

 

[Bespectacled Ape]

Over the years, I've read of other members overloading or putting it close to capacity, none reported a surging situation that I recall.

Did your Lightning come equipped onboard scale? (some builds had it deleted due to lack of supplies).

I'm curious if there is an erratic output from the weight sensor, that's feeding the algorithm bad data and leading to a surging sensation.

Is the readout stable, you might see slight variations, sometimes the scale reset fixes that.

If you have it, go to the scale menu, reset it to baseline [EMPTY], you can calibrate the expected passenger, cabin and bed cargo loads to offset the available capacity for tongue weight.

Attach the trailer, review the tongue loads impact on the scale, with & without the weight distribution hitch supporting the load, is the scale indicating overload conditions?

Adjust your WDH & ride height to it's optimum settings to get the tongue weight into spec.

Wow! There we go. Some knowledgable info. I will get back to you.

 

[Whammy Bar]

Couple questions...

What's the suspension on the truck? You as the factory intended? Or have you done any leveling or suspension changes?

Have you by chance driven over the same locations that caused the surging without the trailer attached? If so, how does the truck perform?

--

My Lariat before the Eibach suspension change was a floaty POS over rolling bumps and abrupt overpass transitions... It was downright laughable and scary. If it had a trailer attached, there's no doubt in my mind it'd probably translate into something similar to what you're describing now.

 

[RickLightning]

Wow! There we go. Some knowledgable info. I will get back to you.

Really? Guess you missed the go weigh the truck and trailer at the CAT scale...

 

[Yellow Buddy]

Really? Guess you missed the go weigh the truck and trailer at the CAT scale...

Perhaps the scientist just needed more detailed steps instead of us coming across as opinions.

@Bespectacled Ape

- I am assuming your description of surging is accurate. Ie, it is occurring on accel/decel conditions regardless of whether you physically touched the brakes.

If you had a Tekonsha, you should be familiar with the calibration settings. If you have no performed the exact same steps on your Ford, you have NOT calibrated your brakes.

The Tekonsha manual talks about selecting hydraulic or electric. It goes into setting effort levels. It goes into calibration of gain. I’ve attached those to this post.

Those same instructions are in the video I posted earlier and is the most likely culprit to your issues.

They are similiar because I believe Tekonsha is a Ford supplier…for their brake controllers.

Your Ford is different from a gas truck. Even with 1pedal driving off, your truck can enter regenerative braking, which can trigger the trailer brakes. If not configured properly, that can cause an engagement/disengagement depending on how smooth your pedal engagements may or may not be.

That is assuming the description you provided of slowing. If you are holding a constant speed and you feel a jerking, it may not be surging and may be porpoising, which would completely eliminate the brake controllers being the culprit.


Self Edited for being snarky.

 

[Ishkatan]

I created a separate surging thread since this seems focused on heavy towing while I experienced surging while towing a very light trailer.
https://www.f150lightningforum.com/forum/threads/surging-towing-light-trailer.29765/

 

[V8Nissan]

I experience this oscillation in my 2023 XLT extended range with 34 foot 8500lb trailer. Happens when decelerating in one pedal driving while rounding a corner on uneven terrain. It's like the regen braking applies and releases in a harmonic fashion. I also experience shuddering in reverse at low speeds sometimes.

Towing a 10k RV with Max Tow (10k) and extended batt. Have chain-style WDH. Tires are all pressured up etc etc. Cruise is off.

Starts surging when I hit a rolling bump. Not doing more than 55 mph. Feels like it is a brake controller software issue but I have turned the sensitivity all the way down and it does not improve. Could feel like a surge brake oscillation but I don't have surge brakes. Hitch moves a little in the receiver but I don't hear any sharp knocking like that would be the problem. Surge is far too big for it to be just the hitch anyway.

My best guess (judging from the sloppiness of Ford's programming and lag of the onboard computer) is that the truck is sensing a sudden forward or rearward motion and electronically reducing throttle input, resulting in a harmonic resonance (oscillation).

BTW surging is a straight forward and straight back motion, and it is extreme enough to do damage. Experienced advice would be appreciated.

 

[Bespectacled Ape]

My XLT definitely has a tip gauge/slope sensor.

I gave up on these guys since they were so full of insults. Not making sense. They seem all bluster/no knowledge.

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