Unintended Acceleration in 4L

[FastDriver]

Anybody else see this issue. I took my Outer Banks Sasquatch on the trail finally (Brown Mtn in NC - nice trails) and found when moving slowly in 4L with little or no pressure on the gas pedal occasionally the engine would try to rev up and I kept having to hit the brakes. Normally it would be at about 900 RPM before this happens. I have not seen it happen in normal modes - only in off road mode.

Sponsored

 

[contented]

Yup, it’s happened to others as well as me. I’d hoped an over the air (OTA) would clear it up, but no such luck. I will say, however, it’s been a little less frequent lately. In a recent Moab trip where we did Tower Arch, Fins & Things, Steelbender, and Poison Spider, it only did it one time.

 

[fields_day]

Yep, all the time. Just used to it by now. You can switch to manual mode to reduce it.

 

[SierraBronco]

Did this to us a lot. Seems to be due to defaulting to second gear in 4L. Bronco shifting into first is suspected as the culprit. Start using manual and drop it to first, especially when going downhill. See if that does anything for ya

 

[Ford Motor Company]

Anybody else see this issue. I took my Outer Banks Sasquatch on the trail finally (Brown Mtn in NC - nice trails) and found when moving slowly in 4L with little or no pressure on the gas pedal occasionally the engine would try to rev up and I kept having to hit the brakes. Normally it would be at about 900 RPM before this happens. I have not seen it happen in normal modes - only in off road mode.

Hi there, if you'd like me to look into your concern, please send us a DM with your VIN and Ford dealer info.

 

[brettclutch]

I have the same thing happen to me. Specifically, when going down over the crest of a mound and I expect the same engine compression going down as I had going up (gear) but all a sudden I have a surge of speed and I have to emergency hit the brake. The advice to go to manual mode is probably the solution but haven't tried it yet. It doesn't happen consistently and only happens 2 or 3 times a day when doing trail running in 4L. I almost wondered if it was expected and just inopportune shift by the computer but it is so strange to me that it hold the gear and engine compression MOST the time as we want off road (wonderful) but every so often it lets go. The inconsistency of it is what makes it strange to me.

 

[Robs]

Did this to us a lot. Seems to be due to defaulting to second gear in 4L. Bronco shifting into first is suspected as the culprit. Start using manual and drop it to first, especially when going downhill. See if that does anything for ya

Yes. I believed that to be a trans shifting issue on the trail in 4L. It’s a bit unsettling when it first happened but one Gets to expect it

 

[SierraBronco]

Yes. I believed that to be a trans shifting issue on the trail in 4L. It’s a bit unsettling when it first happened but one Gets to expect it

It always seemed to happen at the worst time, like when trying to navigate slowly downhill next to a cliff and while turning. The first few times it happened I thought mrs sierra bronco was messing around, but at a really inappropriate time but at least she conquered her fear of heights

Rather than expecting it to randomly happen (random=pointing downhill trying to go as slow as possible) we prefer using manual and not worrying about it.

 

[Valhalla]

Hi there, if you'd like me to look into your concern, please send us a DM with your VIN and Ford dealer info.

This happes to me a ton!!! if you are in 4L under power and it shifts to first good luck stopping!!

 

[murphtron]

Did this to us a lot. Seems to be due to defaulting to second gear in 4L. Bronco shifting into first is suspected as the culprit. Start using manual and drop it to first, especially when going downhill. See if that does anything for ya

Same for me. Happened last week. Putting it in M is the way to go. It is a bit unsettling.

 

[nipeej]

This has happened to me also. When going down hill from a stand still it seems to upshift from 1st gear to 2nd or 3rd. Has done this in 2 high also.

 

[dgorsett]

So far my Bronco's been good, but it happens in my F250. Even in M. It will rev in first low range going downhill, it will actually go slower in second. It's like unburnt fuel accumulates when holding back and the truck automatically gives it throttle to burn off fuel. In second it doesn't hold back so hard, fuel doesn't accumulate and it doesn't have to burn it off. You do need to give it more brake than you would with a proper functioning first though.

 

[Oldhippie]

Happens in manual too…got in the habit of putting my foot on brake before downshifting…

 

[Valhalla]

Glad to say mine did this none on the last trip! It has so many times though. Once in a half open throttle to climb a steep rock. At the top it felt like WOT in first. Slammed the bumper into the next rock. I had both feet on the brake with no effect.

 

[murphtron]

Holy shit this happened again. Was coaching a friend on the one sketchy part of Mazourka Canyon downhill and I screamed “slow down”. He said it suddenly accelerated. I believe him as he has a lot of track time (no off-road time) and is a great driver. Put it in M after that and all was fine. Fun trail though! Beautiful. Easy with one section where it’s steep rocky and off camber for maybe a mile.

Sponsored