Bronco Free Rolls (Falls) Off Steep Hill!!

[RobBob22]

All things considered, maybe there were things you could have done better but in the end unexpectedly rolling down a hill backwards when you're already hitting brakes , in my view, using a tree to stop is still on the list of reasonable options to get stopped.

I do believe you probably lost all your vacuum boost, it's hard to say from there if you could have put enough pressure even with two feet on the brake to get stopped, we'll never really know, after that first jostle it's possible your foot wasn't even on the brake at all anymore.

Maybe, maybe ABS got confused, but if you were in 4L i think some traction features are limited if i recall. I think most reasonable explanation is lack of boost and enough foot power in the moment.

Edit:

just to try, I have a driveway with a 25+ degree slope. Shutting off the engine and rolling downhill forward I got maybe 3 good pumps of the brake with boost on the 4th the pedal got stiff and I had to to put a significant amount of pressure on the brake to come to a stop. I could see reverse being even more challenging. Also, having stalled on the trails a few times I’ve found the assisted restart is pretty quick, even some pressure on the clutch will get that starter moving.

I will say after rewatching the video it does somewhat look like you were possibly gassing in reverse. It wouldn’t be impossible to go from crawl to reverse by accident, I’ve done this once myself.

With all that said, I do believe if this vehicle had a manual pull cable E-brake much of what happens could have been prevented. This is hands down my biggest complaint about the manual bronco.

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[mike8675309]

Someone more knowledgeable than me please chime in.
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...
Since day one I noticed you can’t 3 pedal, feather, pop the clutch, and/or brake boost. It either smokes it or stalls. It doesn’t let you use the clutch as an additional tool to control power.

The system really wants you to pick the “right” combination of 4L/4H and gear, engage the clutch fully, then slowly chew over the obstacle. But you can’t always do that, so you try to ramp up the torque/rpms. When it stalls while trying to pop over an obstacle, it is so wound up, it actually throws you back. I could hear it.
...

I have never had to do anything I would call ramping up the torque/rpms.
On obstacles, I've had zero issues feathering the clutch as necessary.
In low range and on an obstacle you won't be able to "pop the clutch" to get the vehicle to do much. The 2.3 doesn't have enough engine mass but it has plenty of vehicle mass. The Bronco also has a fairly compliant suspension, so a lot of energy that goes into getting over an obstacle gets put into the suspension. I really thing any "winding up" or throwing you back is related to the suspension loading up and unloading.

 

[mike8675309]

Some lessons.

• Don't try to start the vehicle if you are already moving backward.
• Your best bet is to slam both feet on the brake pedal and push as hard as possible, particularly if you don't have assist. Engage the emergency brake.
• Then steer.

Nothing about this list is unique to the bronco—just a general rule of manual transmission vehicles.

 

[2dogcamp]

All modern vehicles have data recorders that record data up to an impact. When you take the vehicle to Ford they should be able to retrieve the data of Throttle, Brake, Clutch and Gear positions for a period of 30 seconds prior to impact. That would tell the story of what happened.

 

[Techun]

If your battery is low on juice even just a little too much, and it doesn't take much since the starter draws so much power, the A.S.S. stops working. The system will disable itself if the battery isn't fully charged. I was driving a short distance back to back a few times and my battery didn't charge enough in between stopping and parking and my A.S.S. stopped working.

If you were crawling along, stopping and starting while waiting for others or just using that A.S.S. to restart your engine, while using lights or anything else that may let your battery drop even a little the A.S.S. disables itself. It happened to me on the trail, where an auto start didn't happen, I remember having to push the start button myself, but I didn't know why until the A.S.S. was disabled again in the city.

This time, I noticed the engine still running while stopped at a light and I hadn't hit that A.S.S. What had happened is, the battery was not getting enough time to charge due to too short of distance being driven between shutdowns and it disabled the A.S.S. After investigating I found in the dash's menu where it tells you when the A.S.S. is disabled due to charging.

So, if you were depending on the A.S.S. and it was disabled without you realizing it was, it would have felt just like you described.

Why do you think your ass stopped working due to low battery charge?

I find it extremely unlikely that your new battery would be drained due to ass usage. A hot engine takes very little to start it back up.

 

[mcinfantry]

All modern vehicles have data recorders that record data up to an impact. When you take the vehicle to Ford they should be able to retrieve the data of Throttle, Brake, Clutch and Gear positions for a period of 30 seconds prior to impact. That would tell the story of what happened.

Correct
ONLY if the system recorded it
Not all events are recorded on the EDR

 

[Arrowbear Rider]

Why do you think your ass stopped working due to low battery charge?

I find it extremely unlikely that your new battery would be drained due to ass usage. A hot engine takes very little to start it back up.

It was the opposite, the A.S.S. was not functioning due to too little battery recharge, I was driving too short of a distance between the engine shut downs and the voltage dropped. I had been driving under a mile, thru a residential area and parking; then starting and driving home at night with lights on and parking. Driving less than a mile both ways at too low of speed to fully recharge the battery and with the lights on too... this happened over and over again daily through out the week until the battery got too low, and then the A.S.S. disengages itself.

Then, when I left the community and I got to a stop light, the battery was too low and the A.S.S. was off and that's when I saw that it was turned off by the system. The battery never recharged enough and over multiple starts the voltage dropped and THEN the A.S.S. stops working. I just happen to experienced a low voltage A.S.S. disengagement both on & off road, so I was familiar with both occurrences and how they feel.

The charging system doesn't need a big drop in voltage to shut things down to protect your battery and the ability to restart, just look at how, on a hot or cold day, your HVAC operation coincides with your A.S.S... The A.S.S. shuts down with several restarts left on the battery, to preserve the battery.

If you look through your dash's menu there is a place that shows when a function is turned off by the system or if all is operating normal.

 

[FloridaBurgBronco]

UPDATE***SO THERE WAS A POWERTRAIN MALFUNCTION CODE I FOUND A FEW DAYS LATER THAT HAPPENED JUST BEFORE THE INCIDENT, THE TRUCK IS AT FORD NOW, SO I WILL DO A FOLLOW UP VIDEO WITH MORE ANSWERS ONCE I HAVE THEM***

 

[Bmadda]

We shouldn’t have to do it. Ford needs to rethink having vacuum boosted brakes on a turbocharged vehicle (just dumb). The V6 already has electric boosted brakes.

The electric boost is WAY worse! One popped fuse and you have no rear brakes at all, and unboosted fronts! Two feet won't stop you on flat pavement! I have experienced that, and YIKES!

 

[harpo]

I think the only thing you could have done to safely get through it was:
1) dump the clutch (assuming trans still in gear...any gear)
2) put both feet on brake pedal and squeeze down as hard as you could
3) set Ebrake
4) apply clutch and restart engine
5) put in neutral, making sure the Ebrake would hold you on that hill
6) hop out and close the hood because you popped it in a panic reaching for the Ebrake.

When you think about it that's quite a checklist in a high stress situation! Or like I said earlier, if you had been allowed to restart your engine, you would have regained control. I see this as a software flaw! I just played around w/crank in gear in the driveway to see how well I could use it, and it's SO WONKY. If you step on the clutch, the dialog box on the dash disappears, it reappears if you release the clutch, you have to scroll down to select "yes", then hold the brake pedal, and hold the start button. If you hold the brake too hard it cant start, if you release to early it says "crank in gear cancelled" and doesn't allow you to try again. This would be too difficult for me in a stressful situation I think! I do love my 6g Bronco, but I think the software REALLY needs work!

I played around with the crank in gear the past days too. Pretty much the exact same experience as you on the first day. The second day I got more comfortable with it but even then wasn't sure I would ever actually use it.

What I thought was really terrible was you have to stall it to use it.

Plus I hadn't realized that in 4l it does not automatically restart when you push in the clutch.

The automatic restart really screwed me up initially. I'd accidentally stall in 2h, push in the clutch then push the start button which turned it off.

 

[FloridaBurgBronco]

I played around with the crank in gear the past days too. Pretty much the exact same experience as you on the first day. The second day I got more comfortable with it but even then wasn't sure I would ever actually use it.

What I thought was really terrible was you have to stall it to use it.

Plus I hadn't realized that in 4l it does not automatically restart when you push in the clutch.

The automatic restart really screwed me up initially. I'd accidentally stall in 2h, push in the clutch then push the start button which turned it off.

Yeah, I want to go through some actions and scenarios once I get it back. I did comfirm what another said that you can't pop clutch start a 6G Bronco, how disappointing. I can't remember now, but I believe I have auto started in 4L, but I could be wrong. Because I have stalled it a few times here and there. I'm not expert at off roading, but I'm not a novice either, but I still occasionally have clutch/gas inputs errors that I have to correct.

 

[harpo]

Yeah, I want to go through some actions and scenarios once I get it back. I did comfirm what another said that you can't pop clutch start a 6G Bronco, how disappointing. I can't remember now, but I believe I have auto started in 4L, but I could be wrong. Because I have stalled it a few times here and there. I'm not expert at off roading, but I'm not a novice either, but I still occasionally have clutch/gas inputs errors that I have to correct.

I thought I had auto started in 4l too and didn't understand why it wasn't working when I was playing with 4l the other day.

So I looked at the manual... The manual told me when you put it in 4l it automatically turns off the ass.

 

[FloridaBurgBronco]

I thought I had auto started in 4l too and didn't understand why it wasn't working when I was playing with 4l the other day.

So I looked at the manual... The manual told me when you put it in 4l it automatically turns off the ass.

Yeah I have no idea now that I haven't driven it in almost a month. I can't remember all the particulars.

 

[Bmadda]

I thought I had auto started in 4l too and didn't understand why it wasn't working when I was playing with 4l the other day.

So I looked at the manual... The manual told me when you put it in 4l it automatically turns off the ass.

I have had mine over a year, and have wheeled quite a bit in 4L, and I WOULD SWEAR, it has restarted in 4L when I pushed the clutch, but now I can't seem to duplicate that! Maybe I imagined it? All this automation has a negative effect on the driver sometimes!

 

[harpo]

I have had mine over a year, and have wheeled quite a bit in 4L, and I WOULD SWEAR, it has restarted in 4L when I pushed the clutch, but now I can't seem to duplicate that! Maybe I imagined it? All this automation has a negative effect on the driver sometimes!

I think it's the antistall function. We think we stalled because in an old school rig it would have stalled, but the anti stall kicks in at the same time we are pushing in the clutch so we think it restarted but it never really stalled.

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