@Fordtechone - collision assist slammed on the brakes in heavy snow

[Small Town Raptor]

My son was driving home last night during a pretty heavy snow squall and it triggered the pre-collision assist. The vehicle emergency braked in the middle of the road and he couldn't move for about 5 seconds....despite pressing the gas.

@FordTechOne have you ever seen or heard of this?

Pretty unnerving....luckily no one was behind him.

 

[Mossy 150]

That's some big ,heavy snowflakes to make it think it was a vehicle. As big as the ones in Washington DC

 

[FordTechOne]

My son was driving home last night during a pretty heavy snow squall and it triggered the pre-collision assist. The vehicle emergency braked in the middle of the road and he couldn't move for about 5 seconds....despite pressing the gas.

@FordTechOne have you ever seen or heard of this?

Pretty unnerving....luckily no one was behind him.

Haven’t heard of that happening, sounds like the radar sensor (with adaptive cruise) or camera (without adaptive cruise) must have picked up on the heavy snow coming toward the front of the truck.

 

[smurfslayer]

A point of clarification:
as I understand it, pre-collision assist only primes the brakes for a maximum braking, and once you touch the brake pedal, it’s full stop, but it doesn’t automatically stop. I’ve got a ’17, so maybe it changed ?

did your son press the brakes?

Adaptive cruise will definitely drop anchor on you abruptly if needed.
I’ve seen adaptive cruise disabled in heavy snow, basically it caked up on the bumper and obscured the sensor. I figured no great loss, I wasn’t setting cruise control in the snow anyway! I swatted the snow off and the alert was gone next start up.

I think the Rap cuts power as part of stability control, and when that happens, you don’t have throttle control at all. I noticed this on the pea gravel course at Raptor Assault and I’ve forced in my Rap.

 

[Small Town Raptor]

As I understand it, the 2019+ have a 3 stage system.
Stage 1 is the Alert
Stage 2 is brake prime
Stage 3 engages the break.

It came to a dead stop and wouldn't budge with his foot on the gas. Probably an isolated incident. You can also adjust the sensitivity of the system in the settings. I may dial it back.

 

[bluesmurf]

My son was driving home last night during a pretty heavy snow squall and it triggered the pre-collision assist. The vehicle emergency braked in the middle of the road and he couldn't move for about 5 seconds....despite pressing the gas.

@FordTechOne have you ever seen or heard of this?

Pretty unnerving....luckily no one was behind him.

I bet that since you were driving in snow, either the sensors built up a snowpack on them and engaged the system. Or, a snow pack on the front dislodged and began sliding down in front of the sensor.

 

[Old-Raptor-guy]

All this technology is a catch 22. Nice (hell amazing) when it works but when it doesn't it can be nuts/shit show.

My example would be "trail control" where you can set speed 10pmh or lower on a trail.

Well I was on a pretty rough trail, set it to 5pmh. Was going great until I came up to a shelf about 10 inches tall.

Got to it and the truck stopped, computer slowly applied throttle until it climb over which was probably damn near 100% throttle.

Off to the races on a rough ass road we went.

It was like going up to obstacle it applied 0-10-20-30-40-50-60-70-80-90% throttle and HAD to drop throttle 90-80-70-60-50-40-30-20-10-0%

It was all of 5ish seconds but it was unnerving.

Obvious to me that a human can react quicker to abnormal/extreme circumstances.

The 30 minutes prior I thought it was pretty cool.

I have not used trail control since.

 

[GordoJay]

All this technology is a catch 22. Nice (hell amazing) when it works but when it doesn't it can be nuts/shit show.

My example would be "trail control" where you can set speed 10pmh or lower on a trail.

Well I was on a pretty rough trail, set it to 5pmh. Was going great until I came up to a shelf about 10 inches tall.

Got to it and the truck stopped, computer slowly applied throttle until it climb over which was probably damn near 100% throttle.

Off to the races on a rough ass road we went.

It was like going up to obstacle it applied 0-10-20-30-40-50-60-70-80-90% throttle and HAD to drop throttle 90-80-70-60-50-40-30-20-10-0%

It was all of 5ish seconds but it was unnerving.

Obvious to me that a human can react quicker to abnormal/extreme circumstances.

The 30 minutes prior I thought it was pretty cool.

I have not used trail control since.

Try going down a steep hill covered with grapefruit-sized rollers. I thought I was going to get whiplash. It was alternately gunning the engine and slamming on the brakes. After messing with the techy features like trail assist and that new-fangled autoyomatic tranny, I just use manual mode and my foot off road. It's much more pleasant and relaxing.

 

[Oldfart]

That would definitely surprise/scare you if it slammed the brakes! I have mine set to warning only, just to avoid having something like that happen. Several times the warning has gone off when someone is making a 90 degree right, in front of me on a 50 mph 2 lane and as I'm going around them to pass by, the system sets off because it thinks I'm going to rear end them, even though I'm not even close to anything like that.

How many of you have yours set to actively brake for you?

 

[downforce137]

i turned it off the first time driving in a downpour at night, while going thru a green light in the country darkness and the dash turned red, and all the chimes started.. never looked back.

im sure theres plenty of situation where this system is very useful, but bad weather isnt one of them. too many other factors in play. at least nothing bad happened, and no collisions happened, while AI was avoiding a collision with a snowflake...