Accelerating on its own when crawling.

[BBJ BRONCO IV]

every time I have been in 4 low for a while crawling, the truck accelerates gently on its own for a few seconds. Freaked me out the first couple times. Especially when it happened at a most in opportune moment, going down a steep boulder trail. I have not talked to my dealer (who I trust) yet.
2.7 Sasquatch. has anyone experienced this?

Sponsored

 

[Lil Red Broncette]

I have 2,900 miles on my Bronco Base and a couple weeks ago I had an experience in a parking lot in 2H. I had let off the brake and it started moving a little as I expected, but as I was thinking of touching the gas to get it to move a little faster, it accelerated on its own. Not fast but more than I expected it to do without me giving gas. The speed didn't get above what I wanted it to, actually in some psychic fashion it was right about what I wanted but I never touched the gas.

After that experience I tried a couple other times and got the initial slow movement but not the extra speed like it did that time.

 

[gjptennis]

every time I have been in 4 low for a while crawling, the truck accelerates gently on its own for a few seconds. Freaked me out the first couple times. Especially when it happened at a most in opportune moment, going down a steep boulder trail. I have not talked to my dealer (who I trust) yet.
2.7 Sasquatch. has anyone experienced this?

I actually had his happen on 4 separate occasions yesterday on the trails here. Freaked me out a bit as I was crawling over some rocks and next thing I know my Wildtrak lurched forward with no accelerator input from me.
I am going to call my dealer tomorrow and see if they might know something

 

[dgorsett]

My F250 does this in low range crawling downhill. I have to ride the brakes. I think it has to do with rich burn loading up and the truck giving throttle to burn it off, annoying.

No issue with the Bronco yet

 

[Dream_Solventless]

Is it the 1/2 or 2/3 shift in 4lo? I’ve noticed it in 2hi leaving my driveway a few times. It almost seems like it holds/carries rpm enough to let the transmission shift and as it slips into the next gear it lurches forward. Seems to happen to me at 4-6 mph or so
Oddly enough, I installed the ford performance tune last week and I’ve noticed the transmission seems to defuel harder now between the first few shifts at light throttle and I haven’t noticed it lurching forward. I’m not sure if it’s something they (engineers) changed or if it’s just to help the trans from a little extra power.

 

[BBJ BRONCO IV]

Thanks for the replies. At least I know I’m not alone. It does appear to be a (mis)engineered action. I will see what the service manager has to say and reply back. If you get any more info please share.

 

[BBJ BRONCO IV]

I have 2,900 miles on my Bronco Base and a couple weeks ago I had an experience in a parking lot in 2H. I had let off the brake and it started moving a little as I expected, but as I was thinking of touching the gas to get it to move a little faster, it accelerated on its own. Not fast but more than I expected it to do without me giving gas. The speed didn't get above what I wanted it to, actually in some psychic fashion it was right about what I wanted but I never touched the gas.

After that experience I tried a couple other times and got the initial slow movement but not the extra speed like it did that time.

that is really strange!

 

[BBJ BRONCO IV]

I actually had his happen on 4 separate occasions yesterday on the trails here. Freaked me out a bit as I was crawling over some rocks and next thing I know my Wildtrak lurched forward with no accelerator input from me.
I am going to call my dealer tomorrow and see if they might know something

this sounds just like hat mine does.

 

[BBJ BRONCO IV]

Is it the 1/2 or 2/3 shift in 4lo? I’ve noticed it in 2hi leaving my driveway a few times. It almost seems like it holds/carries rpm enough to let the transmission shift and as it slips into the next gear it lurches forward. Seems to happen to me at 4-6 mph or so
Oddly enough, I installed the ford performance tune last week and I’ve noticed the transmission seems to defuel harder now between the first few shifts at light throttle and I haven’t noticed it lurching forward. I’m not sure if it’s something they (engineers) changed or if it’s just to help the trans from a little extra power.

your shift pattern would be frustrating. My acceleration happens after going very slowly for a period of time In first gear.

 

[BBJ BRONCO IV]

My F250 does this in low range crawling downhill. I have to ride the brakes. I think it has to do with rich burn loading up and the truck giving throttle to burn it off, annoying.

No issue with the Bronco yet

that is what I was thinking. Kind of like how my old bass boat engine loads up after idling fo a while. but it is not brand new! Yes, annoying. I’m glad your Bronco isn’t doing it.

 

[kevin.gt]

Did you have it in manual mode?

This has been brought up a few times. Happens to me if I forget to go to M especially downhill off-road. Say truck is in 1st and incline causes truck to speed up a little, sometimes it’ll upshift causing it to accelerate.

 

[KABQ]

Mine did this to me in almost identical circumstances. It was even more frustrating because there's almost no brake pedal feedback so it's hard to react appropriately. In my case it was always the vehicle deciding to grab second gear.

 

[Lil Red Broncette]

Is it the 1/2 or 2/3 shift in 4lo? I’ve noticed it in 2hi leaving my driveway a few times. It almost seems like it holds/carries rpm enough to let the transmission shift and as it slips into the next gear it lurches forward.

I had posted previously about experiencing this acceleration and like you felt it may have been the transmission shifting making it seem to lurch forward. Today I had this happen with my Black Diamond and my Black Diamond has a manual transmission. So the lurching forward/acceleration doesn't seem necessarily linked to a shift. I was moving out of the driveway just at idle when it happened. It was like it changed to a higher idle for some reason.

 

[BroncoAZ]

The manual trans trucks will apply more throttle at crawl speeds if they think you are going to stall while climbing an obstacle or grade. I’m not sure if the auto does something similar, I wouldn’t think it would need to.

 

[Razorback]

Happened several times to us in Colorado. We were on the rocks on Mineral Creek. Auto, 2.7l, 4L, around 7-10mph. I was on the breaks each time it occurred. It's happened a few times prior in 2H after I had been on the gas and just thought it was a delayed spool. Now I expect it in 4L just so it doesn't become catastrophic.

Sponsored