Rx400h "lurches"

[tommy275]

Hi all.

I'm really liking my 2007 RX400h, with one major exception.

I've noticed that the car "lurches," for lack of a better word, when i'm at a steady cruising speed. Between 40-70 mph, i notice that the car will toggle between charging the battery, and having the electric motor kick in. During this back-and-forth, there's a very noticable lurch, kind of like when people drive with a constant pumping of the gas pedal, or when a stiff wind hits the car and it slows up a bit. it happens when i use cruise control as well, so it's not as though my foot is spazzing out.

has anyone else noticed this? the car has less than 1000 miles on it, and i'm kinda hoping that it will all normalize over time as things "loosen up." But, I'm not convinced it will so i'm considering taking it in so someone can look at it (and subsequently, no doubt, tell me that i'm imagining it).

help!

neck hurting and slightly seasick,

tom

[RX400h]

Maybe I've become accustomed to it because I do not notice it. It is possible that there may be an adjustment or software update, so do check with the dealership when you have a chance.

[SW03ES]

At those speeds it should be straight running on gas and electric and not moving back and forth...

[tommy275]

took some pictures today.

at about 60-65, on flat road, it toggles back and forth between this (a quick toggle, but a toggle nonetheless):

and this:

another thing i'm very curious about is illustrated in the below pic. why (how) is it that the ICE will drive the electric motor to charge the battery at the same time that the motor is driving the front wheels? this, by the way, happened while sitting still at a toll with my foot firmly on the brake, after about 20 minutes of driving.

i appreciate the feedback. the more i understand the process and hear others' experiences, the better equipped i'll be to talk to the dealer and convince them that something might be amiss.

other than being baffled i love the car (and the attachment functionality on this forum). :)

thanks!

[skyfish400h]

took some pictures today.

at about 60-65, on flat road, it toggles back and forth between this (a quick toggle, but a toggle nonetheless):

and this:

another thing i'm very curious about is illustrated in the below pic. why (how) is it that the ICE will drive the electric motor to charge the battery at the same time that the motor is driving the front wheels? this, by the way, happened while sitting still at a toll with my foot firmly on the brake, after about 20 minutes of driving.

i appreciate the feedback. the more i understand the process and hear others' experiences, the better equipped i'll be to talk to the dealer and convince them that something might be amiss.

other than being baffled i love the car (and the attachment functionality on this forum). :)

thanks!

The "toggling" you have documented here is normal. I see it all the time. However, I don't FEEL it in the lurching you describe. It should be more subtle than that. There could be a learning curve or a break in period since you have so few miles on it. If it hasn't corrected itself by the 5000 mi mark, I would bring it up with service.

Your quesiton about the electric motor both powering the wheels and changing the battery is explained by the fact that despite the single icon on the screen there are actually (2) separtate electric motors doing work here.

[jerryray]

I don't have that problem, However the manager in the service dept said some drivers have reported that. There is a software update that may fix that. Once installed you cannot go back for some reason.

Speak to your dealer and have them test drive the car.

[irieblue]

I posted about this same observation a while ago on this list when my 06 RX400h, had 750 miles on it. (I am taking it in for it's 10,000mile service tomorrow). I can say that the issue seems to have gone away over time, and I no longer notice it anymore. That said, the Accelerator is very sensitive, on this vehcle so I have resorted to using the cruise control alot more than I normally would, as I find I get better mileage that way. In the past I always thought the surging was occuring betwee 60-65 Mph.

Whoever said that the RX 400h runs strictly on ICE when on the highway obviously does not own one. I have seen my 400h run entirely on battery on the highway when cruising along at 65 MPH, of course it doesn't do that for extended periods. Alot of time, though, it will run on both battery and ICE, and yes I know the difference between running the generator and powering the electric motor.

In fact on a recent 1.5 hour/65 Mile trip each way here in Northern CA from San Jose to Monterey Bay (over Highway 17) (which involves driving through the Santa Cruz Mountains ) I averaged 32 MPG going and 25 MPG on the return.

[tommy275]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

[Straub]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

When my dad drives the car I get seasick from the "lurching", I am of the assumption that it's his foot & the sensitive gas pedal that are the culprits because in cruise control I dont need gravol when he is driving.

[tommy275]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

When my dad drives the car I get seasick from the "lurching", I am of the assumption that it's his foot & the sensitive gas pedal that are the culprits because in cruise control I dont need gravol when he is driving.

it's not my foot. and, it happens when cruise control is engaged.

thanks everyone for the input. i will be calling the dealer.

[louis'ride]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

When my dad drives the car I get seasick from the "lurching", I am of the assumption that it's his foot & the sensitive gas pedal that are the culprits because in cruise control I dont need gravol when he is driving.

it's not my foot. and, it happens when cruise control is engaged.

thanks everyone for the input. i will be calling the dealer.

hi tommy

did you get your surge/lurch taken care of? did it go away by itself? i have similar issues, the dealer wanted me to drive it a while. "never heard of it in the '07s." according to them. please let me know how it was resolved.

thanks

[RXREY]

I must have missed something and I hope I don't sound naive,well, I am about cars,nevertheless...what's "ICE"? I keep seeing this pop up. Just so that I know what you are all talking about...Rey

[tommy275]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

When my dad drives the car I get seasick from the "lurching", I am of the assumption that it's his foot & the sensitive gas pedal that are the culprits because in cruise control I dont need gravol when he is driving.

it's not my foot. and, it happens when cruise control is engaged.

thanks everyone for the input. i will be calling the dealer.

hi tommy

did you get your surge/lurch taken care of? did it go away by itself? i have similar issues, the dealer wanted me to drive it a while. "never heard of it in the '07s." according to them. please let me know how it was resolved.

thanks

RXRAY, "ICE" is the internal combustion engine. the gas burning part.

Louis, the surging issue dissipated over time. by 5k miles, i didn't notice it very often. every now and again i'll notice a bit at about 40 mph, but it's nothing like it was.

the dealers are full of ca-ca, or, somehow completely unaware of forums like this one. if they took 2 seconds to find and review these forums, they certainly would have heard of the issue on the 07s.

[louis'ride]

"surge". yes, that's indeed the word i was looking for. "lurch" just doesn't cut it.

after googling "rx400h surge" i see that i'm not alone.

thanks everyone for the insight and input.

When my dad drives the car I get seasick from the "lurching", I am of the assumption that it's his foot & the sensitive gas pedal that are the culprits because in cruise control I dont need gravol when he is driving.

it's not my foot. and, it happens when cruise control is engaged.

thanks everyone for the input. i will be calling the dealer.

hi tommy

did you get your surge/lurch taken care of? did it go away by itself? i have similar issues, the dealer wanted me to drive it a while. "never heard of it in the '07s." according to them. please let me know how it was resolved.

thanks

RXRAY, "ICE" is the internal combustion engine. the gas burning part.

Louis, the surging issue dissipated over time. by 5k miles, i didn't notice it very often. every now and again i'll notice a bit at about 40 mph, but it's nothing like it was.

the dealers are full of ca-ca, or, somehow completely unaware of forums like this one. if they took 2 seconds to find and review these forums, they certainly would have heard of the issue on the 07s.

thank you for validating my experience. when i told them i had the same seasick experience you first reported they suggested i got the idea after reading the forum. no no no. i didn't even know about the forum until i was googling for the problem. when i saw your post i was astonished, i could have written the identical thing verbatim! i did indeed have it at 60. my husband told me i was driving unevenly and he was seasick. yes that did go away, though i still havent done enough long distance highway driving to be sure. right now i am concentrating on the 20-40mpg, its better, but i never know when it will lurch. seems like the engine/battery cant decide who should be in control. will keep you posted, thanks again.

louis (my standard poodle)

[tommy275]

check this thread (on a different forum from this) for more info. you're definitely not alone.

[rgibson]

I had the same problem with mine - showed up after 10k miles. It was fixed via a code update on the transmission (was at 20k)

http://www.lexushelp.com/Ownership/Bulletins/EG/EG020-06.htm

The drawback on the code update is that the ICE kicks in a 40 and the car will almost always run the ICE above 40. I thought this would hurt the mph, but I haven't experienced any impact in the last 7500 miles.

[skyfish400h]

I had the same problem with mine - showed up after 10k miles. It was fixed via a code update on the transmission (was at 20k)

http://www.lexushelp.com/Ownership/Bulletins/EG/EG020-06.htm

The drawback on the code update is that the ICE kicks in a 40 and the car will almost always run the ICE above 40. I thought this would hurt the mph, but I haven't experienced any impact in the last 7500 miles.

Thanks for document!

These are very helpful for those of us who may need a little "help" convincing our dealer's service dept that we have an issue.

[louis'ride]

Yours is a 2006? I am pleased to see the doc in black and white, or rather in pixels. of course they say its not happening in the '07s.

Curious how the identical action showed up in my '07. duh, what a coincidence.

Your problem showed up at 10,000? I only have about 1300 miles, will let it go for another few. Tommy said it pretty much went away after 5000.

Thanks for the link!

[richard4u]

Hi all.

I'm really liking my 2007 RX400h, with one major exception.

I've noticed that the car "lurches," for lack of a better word, when i'm at a steady cruising speed. Between 40-70 mph, i notice that the car will toggle between charging the battery, and having the electric motor kick in. During this back-and-forth, there's a very noticable lurch, kind of like when people drive with a constant pumping of the gas pedal, or when a stiff wind hits the car and it slows up a bit. it happens when i use cruise control as well, so it's not as though my foot is spazzing out.

has anyone else noticed this? the car has less than 1000 miles on it, and i'm kinda hoping that it will all normalize over time as things "loosen up." But, I'm not convinced it will so i'm considering taking it in so someone can look at it (and subsequently, no doubt, tell me that i'm imagining it).

help!

neck hurting and slightly seasick,

tom

hi i feel sorry for you ! Today i went on a 30 mile ride to test my 2007 RX400h to see if it "lurched"

result of highway speed 60-70 with and without cruise i could not detect any lurching whatsoever

then i tried a constant 30 - 40 mph test and tried as i might it was never detectible when the gas motor came on

it was as smooth as silk = i must have gotten a really good one ! i have had it since April 10,2007 1000 miles

i would certainly scream to the dealer and tell him to "fix" your car !!!!!!!! richard4u

[rgibson]

I had the same problem with mine - showed up after 10k miles. It was fixed via a code update on the transmission (was at 20k)

http://www.lexushelp.com/Ownership/Bulletins/EG/EG020-06.htm

The drawback on the code update is that the ICE kicks in a 40 and the car will almost always run the ICE above 40. I thought this would hurt the mph, but I haven't experienced any impact in the last 7500 miles.

Thanks for document!

These are very helpful for those of us who may need a little "help" convincing our dealer's service dept that we have an issue.

Yes, mine is a '06. I had to use the same wording as the bulletin to describe the issue to the dealer, and they then had to replicate the issue (wasn't too hard) - the service dept can't apply a code update with just a printed copy of the bulletin in hand.

In the bulletin, it lists the VINs that where affected. It sounds like Lexus incorporated the newer code in the models manufactured after the listed VINs so this code would be in the '07's.

[louis'ride]

I had the same problem with mine - showed up after 10k miles. It was fixed via a code update on the transmission (was at 20k)

http://www.lexushelp.com/Ownership/Bulletins/EG/EG020-06.htm

The drawback on the code update is that the ICE kicks in a 40 and the car will almost always run the ICE above 40. I thought this would hurt the mph, but I haven't experienced any impact in the last 7500 miles.

Thanks for document!

These are very helpful for those of us who may need a little "help" convincing our dealer's service dept that we have an issue.

Yes, mine is a '06. I had to use the same wording as the bulletin to describe the issue to the dealer, and they then had to replicate the issue (wasn't too hard) - the service dept can't apply a code update with just a printed copy of the bulletin in hand.

In the bulletin, it lists the VINs that where affected. It sounds like Lexus incorporated the newer code in the models manufactured after the listed VINs so this code would be in the '07's.

hmmmm. maybe my car slipped through somehow, seeing that it acts exactly how the '06 problem was described. i am at 1300miles now,

problems are still there, not as frequent or pronounced though i am actually afraid to have something done. you know how when you do something it inevitably affects something else. i will probably wait another 1000 before taking it in. they said if i brought it back the service manager would drive it home for the night (he has an '06) to compare with his. so frustrating that they treat it so subjectively.

stay tuned and thanks for your support.

louis

[skyfish400h]

hmmmm. maybe my car slipped through somehow, seeing that it acts exactly how the '06 problem was described.

Could be. Check the firmware update log under the hood to see it was installed on your car. The document posted shows where the sticker is located and how to tell if it has already received the update.

[BobBass]

Geez...how widespread is this "lurching" problem?

I'm about to give up on Toyota altogether. They can't seem to make a drivetrain/transmission that doesn't have some sort of "driveability" problem at the very least. The new ES/Camry has enough instances of the "shifting flare" that it's effectively off my list. The 330 5-speed in the Avalon/Sienna/Highlander/RX has plenty of owner complaints.

It's amazing to me that the RX is extolled for its ride quality in virtually every magazine review even though it has a relatively short wheelbase. But, combine that with a "lurching" transmission and ride goes out the window. You'd think the CVT would smooth out the power input to the drive wheels.

I test drove an RX400h on back roads and didn't particularly notice anything, but it's probably the kind of thing that drives you NUTS on a highway.

My wife gets carsick very easily if the circumstances are "right." This sounds like something I shouldn't take a chance on. Need some more opinions.

[skyfish400h]

Geez...how widespread is this "lurching" problem?

...

This sounds like something I shouldn't take a chance on. Need some more opinions.

The CVT is amazing. Once you have one you will never want to deal with shifting or an automatic's braindead seeking for the right gear again. It simpley puts the power to the wheels when you need it. Done.

As for the slight surging sensation some have reported, it pales in comparsion to anything you would experinece in a manual or automatic transmission vehicle.

What seems to be happening is the sharing of power delivery between the engine and the electric motor can be mismatched at times which seems to the passenger like you are not holding your foot steady on the gas peddle. "Lurch" is probalby too strong a word for it. Its a control algorithm thing and that is why the code has been updated.

I experienced it for a short time when I had about 1000 mi on the car but have not noticed it since then. Normally crusing is very smooth and surge free even when the electirc motor assist is comming in and out.

In my opion this is not an issue and the HSD drivetrain is world class.

[tommy275]

Geez...how widespread is this "lurching" problem?

I'm about to give up on Toyota altogether. They can't seem to make a drivetrain/transmission that doesn't have some sort of "driveability" problem at the very least. The new ES/Camry has enough instances of the "shifting flare" that it's effectively off my list. The 330 5-speed in the Avalon/Sienna/Highlander/RX has plenty of owner complaints.

It's amazing to me that the RX is extolled for its ride quality in virtually every magazine review even though it has a relatively short wheelbase. But, combine that with a "lurching" transmission and ride goes out the window. You'd think the CVT would smooth out the power input to the drive wheels.

I test drove an RX400h on back roads and didn't particularly notice anything, but it's probably the kind of thing that drives you NUTS on a highway.

My wife gets carsick very easily if the circumstances are "right." This sounds like something I shouldn't take a chance on. Need some more opinions.

as noted here and elsewhere, the problem is correctable. it is also not the norm and not part of the design. but make no mistake about it, it is an issue, rather than only a slight annoyance as some have suggested. if you drove a car and didn't feel anything, the car wasn't suffering from the issue.