Surging

[dedas1hs250]

Hi all to new owners of the HS250. We have owned the car for about a month. It is a great car. My one complaint is an annoying one that takes lot away from the joy of driving the car though. I have noticed that the car surges around 40 to 45 mph and around 55-60mph. I thought maybe there was a problem with the car, but took the car for a test drive with the head mechanic at our dealership. He knew right away the problem. From my reading, it is not with all hybrids, and perhaps with a good number though. The computer is over sensitive trying to accommodate the battery and engine. The mechanic called this "rubber banding" effect. The car surges forward at these speeds on the highway since both the battery and engine are switching " in and out" If you research this topic for all Toyota and Lexus hybrids, it is a common problem for some. For those "some" it is annoying. For the Lexus RX400H, it become enough of a problem from 2005 to 2007, that Lexus found a fix for it in a update of the firmware in July 2007 that stopped the problem, and also improved the gas mileage for those affected. Having the car for only a month and noticing this as a problem, the mechanic said that the car is too new and need to hear more from customers to see if it is an ongoing common problem before they will put a team together to fix the issue. The car is selling like hotcakes from what I hear, and I am anxious for others to see if this is a problem for them as well, otherwise, for the unlucky few that sense this in their cars, it will never be fixed. I have reviewed some in the internet for the Prius and Camry, and there are also isolated incidence with those models too. The mechanic say that the cars are different enough that the same fix doesn't fix all. Too bad. Thanks for reading and posting your experiences. Lexus monitors these forums, so hopefully they will see that this is a problem to address.

[kcpartsguy]

I was driving a service loaner that did this real bad, although my car only occasionally. If I engage the cruise control it goes away completely and if I change drive modes it will lessen the effect.

[dedas1hs250]

I was driving a service loaner that did this real bad, although my car only occasionally. If I engage the cruise control it goes away completely and if I change drive modes it will lessen the effect.

[dedas1hs250]

I was driving a service loaner that did this real bad, although my car only occasionally. If I engage the cruise control it goes away completely and if I change drive modes it will lessen the effect.

Thanks for replying. I think this occurs more than most people think. I think there is under-reporting or that there are some cars that have this problem more than others. I am really surprised that there have been so many people reviewing this topic and nobody else has responded. Either at this site or on the club lexus forum. I lisited the same topic as "cruising and surging" and have over 350 people that have viewed it and nobody but one that has commented beside you. Thanks. It would be great for you to go to the club lexus forum and comment on there to see if it gets the string going. Again, I think if enough people make a fuss, they will address it. Just like the brakes, acceleration, etc. I have not had a problem with the brakes, but have noticed it occasionally. Thanks again.

[benfb]

I was driving a service loaner that did this real bad, although my car only occasionally. If I engage the cruise control it goes away completely and if I change drive modes it will lessen the effect.

Thanks for replying. I think this occurs more than most people think. I think there is under-reporting or that there are some cars that have this problem more than others. I am really surprised that there have been so many people reviewing this topic and nobody else has responded. Either at this site or on the club lexus forum. I lisited the same topic as "cruising and surging" and have over 350 people that have viewed it and nobody but one that has commented beside you. Thanks. It would be great for you to go to the club lexus forum and comment on there to see if it gets the string going. Again, I think if enough people make a fuss, they will address it. Just like the brakes, acceleration, etc. I have not had a problem with the brakes, but have noticed it occasionally. Thanks again.

I've had my HS since the end of December and I've noticed some funny business with the hybrid system (I'm going to start a new thread on that in a minute), but not your problem. However, my highway driving is almost always with the cruise control and LKA turned on, so I probably wouldn't notice. The other day I took a 30 mile stint on I-5 with no cruise control, just to see if my mileage improved (slightly, but not much) and didn't notice any surging. My driving was 55-65 mph.

It's kind of like this thing where there is supposed to be a problem with the braking software. This is observed only when you brake while going over a pot hole. I make a point of not going over pot holes and of going over speed bumps slow enough that I don't need to brake, so I've never observed that problem either.

[KRV]

Hi all to new owners of the HS250. We have owned the car for about a month. It is a great car. My one complaint is an annoying one that takes lot away from the joy of driving the car though. I have noticed that the car surges around 40 to 45 mph and around 55-60mph. I thought maybe there was a problem with the car, but took the car for a test drive with the head mechanic at our dealership. He knew right away the problem. From my reading, it is not with all hybrids, and perhaps with a good number though. The computer is over sensitive trying to accommodate the battery and engine. The mechanic called this "rubber banding" effect. The car surges forward at these speeds on the highway since both the battery and engine are switching " in and out" If you research this topic for all Toyota and Lexus hybrids, it is a common problem for some. For those "some" it is annoying. For the Lexus RX400H, it become enough of a problem from 2005 to 2007, that Lexus found a fix for it in a update of the firmware in July 2007 that stopped the problem, and also improved the gas mileage for those affected. Having the car for only a month and noticing this as a problem, the mechanic said that the car is too new and need to hear more from customers to see if it is an ongoing common problem before they will put a team together to fix the issue. The car is selling like hotcakes from what I hear, and I am anxious for others to see if this is a problem for them as well, otherwise, for the unlucky few that sense this in their cars, it will never be fixed. I have reviewed some in the internet for the Prius and Camry, and there are also isolated incidence with those models too. The mechanic say that the cars are different enough that the same fix doesn't fix all. Too bad. Thanks for reading and posting your experiences. Lexus monitors these forums, so hopefully they will see that this is a problem to address.

Problem: Continued speed surge while on cruise control.

I have had the 250h for a few months now; driven over 5000 miles; mainly on highways. Overall it runs great.

One problem I have noticed is as follows. If I put the car in cruise control and touch the cruise control lever upwards for a fraction of a second to increase the speed, as expected, the speed goes up by a mile or two.

However, if the contact with the cruise control lever is for a couple of seconds or so, the speed continues to surge in an uncontrolled fashion--from 60 to 65, 70, 75 etc. By stepping on the brake, speed does get under control. My wife took it to lexus dealership and drove the car with their mechanic. He told her that this is not a problem and occurs with hybrid cars! I am concerned about this and has scheduled another visit to the dealership. Has anyone else noticed this type of speed surge?

[Steveach]

I have felt the surging as well and will report it to the dealer. I thought it was wind off of other cars at first, but then noticed it on days with no other traffic around me and light winds.

[Mr. Wiggins]

I noticed this surging. It was not strong but I could definitely feel it. I thought it was simply the difference of driving a hybrid, my first. I have had the car about 8 months but haven't noticed the surging lately. I do not use speed control.