Cruise control -- very weird thing happened

I was just driving along in my '06 DC (automatic transmission) on a gentle incline at about 30 mph, coasting towards a stop sign with the cruise control turned on (but I'm 99.99% sure that it was not set/engaged) when out of nowhere the truck kicked down (as if I had stomped fully on the accelerator) apparently by itself....it lurched from whatever gear it had been in to low gear with the tach needle flying up to redline. The only thing is, my foot was not on the gas pedal when this happend because I was coasting to the stop sign...!?!?!?! It totally caught me off guard, so I panicked (as there was traffic stopped at the stop sign not far in front of me) and I stomped on the brake and everything was hunky dory after that. But WTF happened?? It scared the crap outta me. Has anyone heard of such a thing happening?? It was as if the cruise control computer had been "told" to accelerate to maximum. Was it some kind of freak computer bug or something?

The acceleration was so sudden and violent that I'm paranoid that it damaged my transmission or something.

 

I don't even use my cruise control because of this. Let's just say I have my cruise set at 55 mph and I have to pass a vehicle. So I run her up to 65 to get around. Then I take my foot off the gas pedal (cruise is still set). Instead of re-engaging at 55, speed will continue to drop until it is below 50, then it will drop down to 3rd gear, just about red line just to get back up to 55. The speeds have been changed to protect the not so innocent. I mean, who really sets their cruise at 55?

 

Usually to prevent what you describe from happening, I disengage the CC, speed up, pass the vehicle, then slow down to whatever speed I was at before and then re-engage the CC while driving at a constant speed.

But in the case that I described above in my OP, the CC was not engaged to begin with -- it was as if it engaged itself, and decided that it wanted to accelerate at max output without me telling it to do so. It was freaky!

 

Yeah, your deal isn't quite what I've experienced. But I think it's a lame ass excuse for a cruise control. I haven't used mine in years.

 

I very rarely use mine anymore either. I have the automatic and any time I came to a hill instead of dropping down a gear as the load on the motor increased it would slow down and then drop two or three gears and redline to catch up to the previous speed.

Totally f'n irritating.

 

I've used mine a lot over a 9 mile drive to work everyday and sometimes it's ON but in 'cancel' mode (so to speak). I've never had any weird things happen.

Was there any chance that you accidentally bumped the stalk to 'set' it? Although with mine - it doesn't set unless you hold the stalk down for atleast one second.

 

Huh. Was the video you saw related to the floor mat recall? Or was it related to something else? Do you happen to remember the name of the video?

No, I never did figure out what happened. Although one time since that first incident happened I had my cruise control engaged at a low speed (like 35 mph) and as I started to go up a hill, basically the same thing happened again -- it downshifted to first and redlined to regain its target speed (if you want to see what it's like, I'm sure you could reproduce it by setting your cc at 35 then approach an uphill and let it go berzerk).

In the first incident, the only thing I can think of is that I either accidentally or unconsciously set my cruise control as my speed was decaying while coast up a grade and it did the same thing as described above. It lurched so hard the tires squeeled.

Good thing to be aware of, anyway.

 

thats pretty weird. yesterday i noticed my crusie control "magically turned on" but i dont think it was engaged. it was just "ready" because i noticed the green symbol was lit up. But nothing like your experience has ever hapenned to me. I only use my CC on the big highways though. IMO it seems dangerous to drive with it engaged on any other roads with curves and such.

 

Thanks for finding that video. Very interesting. I'm not sure what exactly they mean by "surging" though. Do they mean an actual acceleration or do they simply mean that they need a lot of brake pressure to keep the vehicle stopped at a stoplight?

In any case, I just found this article about an Avalon that sounds very similar to what I experienced.

http://www.leftlanenews.com/toyota-avalon-displays-unintended-acceleration-without-floor-mat.html

For those reading this, note that I started this thread a long time ago, before all the recalls and whatnot.

 

REPLY: I explored the cruise control on my 2010 4x2 2.7L Auto while travelling in the mountains in Nov 2009. Same thing happened on steep upgrades any setting from 55 to 75mph. Fails to hold the speed setting, downshifts to second, almost red-lines before shifting back to fourth, then repeats the pattern.

Using the cruise paddle to disengage takes about 2 seconds to react. tapping the brake seems to be "instantaneous".

I believe it's bad cruise control software because without the cruise control the vehicle can handle the hills quite well just by downshifting to third.

I've stopped using cruise on hills because it just seems to be thrashing the drive train too much.

I'm also beginning to wonder if there is a connection to unexplained acceleration in this.

 

6-spd cruise control ftmfw

 

yeah cruise control sucks in my truck goes 5 above or below what it was originally engaged at

 

Bump.

...in light of recent news headlines (i.e., reports of sudden accelerations due to alleged computer bugs).