2007 Rx400h Awd Maintaining Speed Issues...

[Jeffs2007 400h]

I just purchased the 2007 RX400H AWD with luxury package. The day I brought the vehicle home I noticed that the vehicle was not accelerating correctly. If felt as if I was taking my foot off and on the gas pedal, but I was not. I was depressing the accelerator to get to 60 MPH and trying to maintain at that speed. The vehicle would not maintain the speed manually as well as using the cruise control. I would set the cruise at 60 and it would surge up to 65+ and go drop below 60. It would not maintain speed. The motion was making me nauseous.

I had been talking with the Lexus dealer and they stated to me that there were issues on the 06, but with software changes the issue was corrected.

I took the vehicle back in to have the senior service advisor drive the vehicle so they could experience the rocking motion from slower to faster vice versa. He felt the sensation and agreed that we have a problem. So they kept the vehicle today to take technical scans and send them to California engineers. They have other complaints with the same issue and looking for a software fix.

The Lexus dealer has been wonderful and very concerned about the issue.

I am looking forward to a quick resolution.

Jeff

[RX400h]

Our 2006 RX400h has not had this problem at all. I am sure that a fix is in order for your RX.

Please let us know how it turns out.

[Jeffs2007 400h]

Our 2006 RX400h has not had this problem at all. I am sure that a fix is in order for your RX.

Please let us know how it turns out.

Thanks, I will!

Jeff

[tommy275]

if i'm understanding you correctly, i had the same issue. see thread here.

others have as well. if you search on "surge", you'll find some posts/threads.

someone suggested that they used to have the problem, but it kind of dissapated. at first i didn't believe them, but i have to admit that i don't notice it very much any more. my 2007 is about 3 months old with less than 5k miles. of course when i called the dealer about something else and mentioned the issue, the salesman claimed he had never heard of such a thing. i didn't get around to talking to the service department, however.

rest assured you are not crazy and this is a real issue with some cars. but as i say, it seems to go away for some.

[SOMEONE ELSE'S GOT MY NAME]

Usually the dealer posts these issues in their TSB's ... but I can't find this issue anywhere.

[Jeffs2007 400h]

if i'm understanding you correctly, i had the same issue. see thread here.

others have as well. if you search on "surge", you'll find some posts/threads.

someone suggested that they used to have the problem, but it kind of dissapated. at first i didn't believe them, but i have to admit that i don't notice it very much any more. my 2007 is about 3 months old with less than 5k miles. of course when i called the dealer about something else and mentioned the issue, the salesman claimed he had never heard of such a thing. i didn't get around to talking to the service department, however.

rest assured you are not crazy and this is a real issue with some cars. but as i say, it seems to go away for some.

Hey tommy:

Yes, this link is what I have been experiencing. I feel that a 50K vehicle should not be running this way. I felt likw I was going to get sea sick but in the new car.

Hopefully they have a software fix for this issue.

Jeff

[wb578]

I realize your car is a 2007, but in October 2006, Lexus issued TSIB #EG020-06 regarding this problem in the 2006 RX400h.

The TSIB instructed dealers to flash re-program the Hybrid Vehicle ECU and ECM (PCM). You might want to talk to your dealer about that TSIB and ask them to consider re-flashing your car's system if they haven't already come up with a fix.

Also, the TSIB ends with:

NOTE:

Select premium unleaded gasoline with an Octane Rating of 91 or higher for

optimum engine performance.

The effect of the new calibration may become more apparent after several days

of driving as the ECM (PCM) “learned values” are re–established from the

customer’s driving.