Hesitation in Acceleration

[adavid]

I think that I have seen a thread about this in the past, but I can not find it. I have this situation happen once every 3 months, but in the last week it has happened twice. Though I am not able to reproduce it on demand, here is how it normally happens.

I am coasting at about 20 mph, and then I step on the accelerator for moderate acceleration. At that point nothing happens for what seems like 3 seconds, and then it will downshift and go. In a few cases this has caused me to almost get into an accident. Here is what happened with the last 2 times.

1. I was on a road where the speed limit was 40 mph, and I needed to take a left turn. I was braking down to about 15 mph, and then went to take a left in front of a car that was plenty a distance away coming from the other direction. When I turned and stepped on the accelerator, nothing. I limped across the street in front of the oncoming traffic, which luckily slowed down and did not hit me.

2. I accelerated onto a highway and ended up behind a truck doing 20 mph. As I started to move over to the left, I looked back and there was a car about 150 yards back. I moved over and stepped the accelerator all the way to the floor. Before the Highlander started accelerating at all, that other car was right on top of me, and then passed me not looking so happy.

My dad has a 2010 Lexus RX350, and has had similar problems, so it must be something in the programming to help with gas mileage. Have others had this problem? I feel like I want to put in a complaint to NHTSA. I know that if I bring it into the dealer they won't be able to reproduce it.

Andy

[Dman1]

Originally Posted by adavid

I think that I have seen a thread about this in the past, but I can not find it. I have this situation happen once every 3 months, but in the last week it has happened twice. Though I am not able to reproduce it on demand, here is how it normally happens.

I am coasting at about 20 mph, and then I step on the accelerator for moderate acceleration. At that point nothing happens for what seems like 3 seconds, and then it will downshift and go. In a few cases this has caused me to almost get into an accident. Here is what happened with the last 2 times.

1. I was on a road where the speed limit was 40 mph, and I needed to take a left turn. I was braking down to about 15 mph, and then went to take a left in front of a car that was plenty a distance away coming from the other direction. When I turned and stepped on the accelerator, nothing. I limped across the street in front of the oncoming traffic, which luckily slowed down and did not hit me.

2. I accelerated onto a highway and ended up behind a truck doing 20 mph. As I started to move over to the left, I looked back and there was a car about 150 yards back. I moved over and stepped the accelerator all the way to the floor. Before the Highlander started accelerating at all, that other car was right on top of me, and then passed me not looking so happy.

My dad has a 2010 Lexus RX350, and has had similar problems, so it must be something in the programming to help with gas mileage. Have others had this problem? I feel like I want to put in a complaint to NHTSA. I know that if I bring it into the dealer they won't be able to reproduce it.

Andy

I am sure someone can offer more info on this than me, but it may be an issue with the learning function of the transmission controller. I believe that I read on here that the tranny controls will learn your driving habits and alter at which points that it will downshift or upshift. It is possible that the problem lies with this. Apparently, it can be reset by disconnecting the battery. I haven't done this, but I believe others on here have.

[PhotonDreams]

This is a long shot but you might check to see if that, without knowing it the "Snow" button has been depressed. Press it somewhere safe and see if the behavior you describe match when the "Snow" feature is engaged. My other thought is that even without pressing it the computer is engaging it without any action on your part due to a computer problem. Good luck.

[lets456]

Originally Posted by PhotonDreams

This is a long shot but you might check to see if that, without knowing it the "Snow" button has been depressed. Press it somewhere safe and see if the behavior you describe match when the "Snow" feature is engaged. My other thought is that even without pressing it the computer is engaging it without any action on your part due to a computer problem. Good luck.

Or the "slip control"... I hated that thing in my Avalon. I almost got killed once when I pulled out into traffic and my car stayed at 20 MPH waiting for traction on a dry day then proceeded to speed up. The second time happened when merging onto the highway and I floored it and the car actually slowed down for a second then I hit the "slip control" off and it took off like a rocket. Needless to say from that point on slip control stayed off.... worth checking if you have it.

[nov0798]

Its the computer for the tranny. Alot of transmissions have this issue with the computer. This is easily proved if when you use the sport shift feature it goes away. Its just the stupid computer, thats all.