Truck randomly accelerating on its own in S4

The past 2 months I've had multiple experiences where my truck will randomly start accelerating on its own when I'm driving in S4 or S5. I've had this happen with cruise control on too. Not exactly sure why its been happening but it'll just randomly jump from ~2,000 RPMs to ~5,000 (40mph to ~55) out of nowhere for about 5 seconds. It runs normal, no weird idling issues, and I've also installed no modifications which may cause this to happen. I'm aware that S mode doesn't actually do anything other than limit the highest gear I can go into.

This sounds like a friday post but I swear its not LOL

 

I would examine the entire throttle cable system.

 

I'd part it out.

 

there is no throttle cable. maybe check the accelerator pedal sensor to make sure it's seated. i'd also unplug and clean with electronic cleaner.

 

Do you have a Sprint Booster or Pedal Commander installed on your truck?

 

Nope

 

do you have your foot on the accelerator when this happens? or is your foot on the brake while the truck is trying to accelerate? could just be downshifting.

 

This only happens when my foot is off the accelerator and off the brake pedal. Its only happened in S4 and I do like 95% of my driving in the regular drive gear

 

floor mat?

 

The pedal isn't getting stuck on anything. It'll happen when the pedal is fully depressed

 

There were a couple of posts here regarding that. Look it up.

 

previously, you said it happens with your foot off the accelerator. so not sure what is even happening here.

 

sorry, I mean it happens when the pedal isn't pressed in. I think I worded that wrong

 

Does it instantly jump from 2k to 5k rpm? That would indicate a downshift. Or does it accelerate from 2k up to 5K on its own?
Either way something sounds wonky….

 

Unpopular topic and some people will not believe you. Several threads about this got locked due to name calling and bashing others (from what I read).
I’ve have the issue in the past. Before and after a tune. Usually after letting my foot off the gas but keeping my foot just above it, not touching. Have the OEM OR floor mats, not in the way. I’ve cleaned the MAF sensor and it seemed to stop for a while, coincidence or not, no idea. Here is one of the open threads about it- https://www.tacomaworld.com/threads/my-2021-tacoma-accelerated-on-its-own.764325/page-3

 

Show me pictures and I'll buy you a Coke.

(search the term 'drive by wire' in Wiki)

 

It’s not really instantaneous but it’s quick, it’ll just start increasing on its own for about 3-5 seconds then it’ll go back down like it never happened

 

sounds like the ECU is still learning. I had some weird moments like this when I first got my truck. it went away after 5000 miles or so.

 

Good thing I’ve seen you around or I would swear it’s a friday post lol. There have been other posts about uncommanded acceleration.
From your description of it happening in S4 when you let off accelerator pedal and it going “~2,000 RPMs to ~5,000 (40mph to ~55)” it must be downshifting to S3, and for some reason increasing throttle. Is cruise inadvertently on maybe?

 

Okay, I'm not sure if I've had the exact same issue as you, a similar issue or maybe they're not related at all? But here goes:

A few times I have experienced random acceleration in my truck. I'm pretty sure the RPM's rev'd up, but I didn't focus on that because I was wonder "Why the fuck is my trucking going faster if I'm not pushing the accelerator pedal!?" I have a Sprint Booster on my truck and was worried that was causing the issue. But it happened again after I removed it.

Each time that it has happened there were a few common denominators:

1) The cruise control was on. Also, it was the normal cruise, not the speed adjusting crap. I hate that option.
2) I was on an incline greater than 8-10 degrees. The last two times it REALLY stood out was when I was taking a ramp to change highways, and the ramp that I was taking (I was going from I-20 to US 287) is very elevated. I think it's 5-6 stories off the ground.
3) I pressed the brake when I got CLOSE to the top of the ramp.

So my truck was on cruise control, climbing a some-what steep grade, then I touched the brake pedal. Then...the RPM's (probably, I wasn't watching) rev'd up and I noticed I was going FASTER. This was quickly remedied by me pressing the brake pedal again a bit hard and then I slowed down. Now, the very first time this happened I thought it was my fault, but after it happened a few more times I noticed a lot of commonalities.

I think the truck was still thinking "Hey, I'm in cruise control mode, and I'm going up a steep hill so I'll give it more gas." Maybe there was a lag or time delay for the CC to tell the ECU "Stop delivering constant power and adjusting power"?

I don't know if this helped or just raised more questions.