Truck randomly accelerates on its own

[JohnBronco]

My Raptor has been randomly accelerating on its own this week. I've noticed it 3 times, I'll be driving and all of a sudden it'll accelerate a good 5 mph on its own before I stop it with the brakes. I know that's not a great description, but I also haven't been able to find any threads on this.

I had my truck on jacks for a little over a week while I had my shocks rebuilt and when I started it for the first time Sunday, synch had a battery saver mode message on it when I got in the truck. I know these trucks do weird things when the battery gets low, going to go get it tested but I wanted to ask here if anyone else has experienced something similar, with the random acceleration. Thanks

 

[smurfslayer]

That’s a bit odd. Can you give some more specifics on the truck?
any mods ?
have you noticed any codes ( pull with FORSCAN )?
Under what conditions?
steady throttle? accelerating but mildly? Decelerating?
what drive mode?

I sometimes perceive this in sport mode when coasting. The truck does a kind of ‘rev match’ coming down in rpms, and it can make for a non linear feeling while you’re slowing down.

 

[JohnBronco]

That’s a bit odd. Can you give some more specifics on the truck?
any mods ?
have you noticed any codes ( pull with FORSCAN )?
Under what conditions?
steady throttle? accelerating but mildly? Decelerating?
what drive mode?

I sometimes perceive this in sport mode when coasting. The truck does a kind of ‘rev match’ coming down in rpms, and it can make for a non linear feeling while you’re slowing down.

The truck is a bone stock 2017 with 70k miles driving in normal mode. I'll pull codes later today.

I noticed it the first time I pulled the truck out of the garage with light throttle (not the lurch when you shift from P to D).

Then a second time when I gave it a little throttle at around 20 mph, let off and then it began to accelerate on its own until I stepped on the brake. It happened a few more times but I don't recall what I was doing other than driving at part throttle.

I drove for 2 hours today and it didn't do it.

 

[JohnBronco]

Pulled forscan codes and there wasn't anything there. The condition hasn't returned. I think this was a low battery thing

 

[Booth9999]

My gen 2 would do something silliest when it would upshift when going down hill. It would slightly accelerate as it shifted but only from a 1-2 shift when cold. Like it was raving up to shift but the clutch pack was still locked.

 

[BHook]

Had an 85 corvette do something similar, turned out to be a "Throttle Position Sensor" going bad. It was sending a signal to the computer that I was opening the throttle to accelerate when I wasn't. Today's fly by wire setups have that signal coming from the gas pedal to the computer then the computer tells the throttle body where to position itself to match your gas pedal position. My vette threw no codes, and I assume the f150 wouldn't either (probably cannot self diagnose a bad throttle controller).

 

[scpete24]

My gen 2 would do something silliest when it would upshift when going down hill. It would slightly accelerate as it shifted but only from a 1-2 shift when cold. Like it was raving up to shift but the clutch pack was still locked.

Mine does the same thing on occasion

 

[Coop65]

Same here periodically on deceleration at a slow speed but only happens sporadically…. Curious to hear what everyone thinks too ?? Hasn’t been bad enough that I worried about it though

 

[Booth9999]

Same. Mine just did the same thing in my gen3 this morning. Not a deal. Exciting if you are off the brakes.