former91CavGT

Hi everyone. I am 91CavGT, but I had to re-register because I got locked out by accidentally changing my email to the wrong email address.

In the fall of 2008 my wife and I tradded in her 2005 Toyota Corrolla for a 2009 Scion Xb. All was well umtil about 18,000 miles when I noticed occasionally a weird RPM stumble, mostly around 35 mph. The RPMs will basically go from cruising at about 1500 rpm and they will shoot down to 800 rpm, you feel a slight deceleration, then the rpms go right back up to normal. This occurs on flat ground or slight down hill and with VERY minimal throttle input. I didn't think much of it until last summer when it started getting more pronounced and easier to duplicate at about 32,000 miles. So I took her Xb in to our local dealship to find out what was going on.

About 3 weeks later we get the car back, but it is still not fixed, and the dealership let us know up front that it wasn't fixed as they didn't know what was causing the problem. During the time that they had the car, they reflashed the computer, took computer snap shots of exactly what it was doing and sent them to Toyota, and even replaced the transmission. The service advisor said that Toyota was working on a fix and they would contact me when a fix was ready.

The winter time came and the problem disappeared. It didn't act up anymore until late this spring when tempuratures started to climb. Low and behold, it came back so now with 40,000 miles on the odometer we took my wife's Xb back to the dealership to see if there was an update.

At this time, the service advisor talks to the original tech that worked on the car, he also pulls up the history on the car, then he tells us that Toyota's Field Serivce team had decided that this was a normal operating parameter of the car and that EVERY Xb does this and there is nothing that can be done.

Needless to say, I was not a very happy customer after hearing this news. I told the service advisor that if it was a normal operating parameter of the car then why did it not start doing this until 18,000 miles and why did it stop doing this in the winter time?!?! The service advisor then tells me that he is going to contact a regional rep from Houston and that he was going to contact me.

Later that same evening, sure enough I get a phone call. Yet again I hear that this problem is a normal operating parameter and there is nothing that can be done to fix this as there is no problem. I then ask him that if this was a normal operating parameter then wouldn't it make sense that this would occur since the car was brand new, and that it was ALWAYS occur to the car regardless of the weather conditions? He says yes, and I then proceed to tell him exactly what I told the service advisor. At this time, his attitude changes and he admits that something doesn't sound right. He gives me a phone number to call and asks if I will open up a complaint so this problem can be looked at by some engineers. I call the number and do what he said to do at that point.

So fast forward to day. My wife gets a phone call that there is a group of people coming up from Houston on Tuesday to look at her Xb and that she needs to make sure it is at the dealership by no later than 4 pm.


Here is the original thread on this problem........

https://www.scionlife.com/forums/sho...d.php?t=190160


So how many other people are experiencing this problem? It occurs at 35 to 45 mph. The faster the speed, the more down hill you need to be going, but at 35 mph it primarily happens on perfectly flat road. The rpms will suddenyl drop, you will feel a slight deceleration, then the rpms will go right back up to where they should be.

This is NOT the transmission trying to upshift. If it was, there would be a slight acceleration when the rpm change would happen, not a deceleration.

Sorry for the long post. My wife and I are getting tired of getting the run around and being told that there is nothing wrong with our car when obviously something is not quit right.

2010SWxB

My 2010 does this downhill at higher speeds...except my rpms do not drop since it's a manual trans. At very very light throttle it seems to go into decel/fuel cut mode as if I took my foot off the accelerator. Very annoying..I'm sure its to do with electronic throttle/throttle position sensor(if there is one). On a trip to Vegas, every downgrade it would do this. I hate the electronic throttle in this car with a passion. Especially with a manual trans.

TrevorS

iTrader: (1)

I typically have very little throttle applied (manual shift), but I often notice a slight (but distinct) drop-off followed not long after by an equivalent pick-up cycle. I don't know if it's the minimum step on the throttle plate stepper motor, or something associated with the ECU processing, but it really helps me to prefer an analog throttle ! Yes, it could be due to some tiny motion of my foot, but I've never felt it with an analog throttle car. Sometimes, I really don't care for digital.

wagonbldr

Hey All,
My RS 7 started doing this same thing not long after I got it. Got it new with 2 miles on it. Now have 28k miles and it still does it. I took it to the dealership when I first noticed it. Mine is auto trans and it will suddenly drop like 400 rpms and then bounce back to normal. I can even feel it doing it costing downhill at 65mph sometimes. Dealership said it was normal and didn't find anything out of ordinary. I don't believe it, but not sure what else to do.

former91CavGT

My wife got a call about an hour ago from Toyota/Scion. After testing the car from Tuesday till today, they reported that everything on the car is acting as it should. They call it, "Normal operating parameters".

I asked them "So you mean to tell me that the car is programmed to do this?". All the could respond was everything is within normal operating parameters.

At this point, I have no recourse unless I go through arbitration, which I can not afford so that is not an option for me.

About the only thing that can be done is if enough people go to thier dealer and complain about it.

I don't get mad very often, I can count the times on one hand that I have been really mad my whole life, and this is one of those times.

09BCMxB

Try turning off your traction control for testing purposes.
Don't know if this will help or if you've tried this but what you're describing is the same as what happens when the traction control kicks in.
If the problem goes away or lessens then you have something you can go back to Scion with.
Also, have you tried running 35mph using the cruise control? Seeing what happens can help narrow things down some more.

former91CavGT

I will try turning off the traction control, but at this point, even if I can narrow it down more, Toyota/Scion won't do anything with it.

If you use cruise control, that is the easiest way to make it do this.