Toyota Highlander Hesitation

paterd

Hi,
I have a 2005 Highlander. Ever since I bought it (used) I noticed that when I slow down and do not completely stop, then accelerate, that it hesitates, then it jerks upon acceleration. Is this something normal for a Highlander or should I have it checked out?
Thanks,
Pat

bdyment

Have it checked out. Perhaps one of the software fixes for the transmission will improve the shift quality. However, lately Toyota tranmissions especially V6 models have been having hesitation and flare problems. Hope yours is not one of these.

paterd

Thanks, guess I better do it. I just hate the dealer that is closest to me. I went in for an oil change and ended up $192 poorer (10,000 milecheckup) and they only had the car for 1 hour!

ceaby1

Have had this problem since new on 04 model 6 cyl.

A year ago, the Toyota dealer reprogramed the chip as per the Totota billetin which about cured the problem, but the problem still exists only not as pronounced. The dealer (McDonough, Staunton Va.) is not aware of any new bulletins, and cannot fix the the problem. While this hesitation is not annoying enough to sell the car, it is of suffucient annoyance to me that I would not purchase another.

paterd

Thanks for your comments. I may feel the same way if they can't fix mine. It can get really irritating at times.

wwest

The "hesitation" is the result of an attempt by Toyota, and many other manufacturers of FWD or front torque biased AWD vehicles, to increase the safety factor of these vehicles when operating on a slippery or low traction roadbed surface.

What has happened is that the transaxle shift pattern/sequence/schedule has been changed/revised, beginning late in the last century, such that upon any full lift-throttle event the transaxle will automatically upshift in order to reduce the level of engine compression braking. Engine compression braking which, should the roadbed happen to be slippery enough, will oftentimes result in loss of directional control of the vehicle, or maybe even worse, interfere with the proper operation of your ABS, anti-lock braking system.

So far, all to the good, yes..?

But.

What if, just by pure happenstance you re-apply a fairly serious level foot pressure to the gas pedal almost immediately after the full lift-throttle "event".

The engine RPM has dropped to idle, the transaxle is busily upshifting and now a quick sequential downshift is required and there is no "reserve" ATF pressure source to provide the "means" to quickly provide the downshift.

So, DBW, e-throttle, is used to delay the response of the engine for 1-2 seconds to your new "request" until enough ATF pressure flow is available to accomplish the required downshift.

1001, 1002...GO...!

ceaby1

Thank you for explaining this problem. Is it thus that Toyota cannot fix this without sacrificing stability on slippery surfaces. May I assume that this hesitation would not be present in the front wheel drive only Highlander? Have any other manufacturer of AWD vehicles solved this problem? Any such problems with Chrysler Aspen?
Appreciate your input, wwest.

Carl

jbollt

carl, in regards to what wwest said, you would be wise to research this further. Keep in mind that this is one person's opinion, and not fact presented by Toyota.

wwest

There is a TSB "floating" about issued by Toyota in the spring of 2003 pertaining to the 2003 Camry that very explicitly describes three of the primary circumstances wherein the 1-2 delay/hesitation is most likely to occur.

The 2000 and 2001 Lexus RX300 shop/repair manuals describe a shift pattern wherein upon a full lift throttle event the transaxle is upshifted. A 30 day "pass" to techinfo.toyota.com will get you access to ALL Lexus/Toyota repair/shop manuals and you can verify the above to be across the board for FWD and front "based" AWD vehicles.

Until Toyota redesigns the transaxle to allow a variable displacement ATF pump (as Ford seemingly has done with the new FWD Edge) to be implemented it is likely ALL FWD and front torque biased AWD vehicles will be subject to the downshift delay in the circumstances the TSB describes.

In the alternative they might license the Ford patent and only upshift the transaxle if the OAT is near or below freezing or if VSC/Trac or ABS has recently activated. Or only license a portion of the patent and then maybe even only upshift if the brakes are applied shortly after a full lift-throttle event.

Otherwise, yes, just one person's opinion.

edmunds34

My wife and I also have a 2005 Highlander and has the same problem. I took the car to the dealer and they have checked, ran test, and made adjustments, but still have the same problem. The dealer said that this is a known problem, which many of dealers have provided feedback to Toyota, but not sure if will be fixed or not.

They also said that this is common in most of Toyota.

R

wwest

Yes, somewhere along about late in the last century Toyota/lexus started reducing the FIXED displacement of the gear type ATF oil pump. Previously, historically, this pump had enough capacity with the engine at idle to provide enough pressure/flow for a QUICK downshift immediately following an unshift.

Can you imagine, then, the level of ATF that was pumped needlessly, ported right back into the sump, while cruising for hour upon hour in OD at ~2200-2700 RPM..??

Waste, HEAT...!!

So lots of "gain" was to be had should one be able to reduce the displacement of that gear type ATF oil pump.

As so it was DONE...!

So...

Downshift into 1st below 10-0 MPH with the engine at idle BEFORE coming to a complete and full stop...

NOT.

Feeling, 10-0 MPH, as if being "bumped" lightly from behind...??

WEll..yes.

Most stick shift drivers might downshift 10-0 MPH but disenage the clutch....

So the new shift technique/pattern/schedule adopted along with the downsizing of the ATF pump "back when" involved NEVER downshifting in circumstances wherein due to lack of pump volume the clutches could not be quickly and firmly seated.

But things went awry...

The drivers did not exactly cooperate.

So the '99 RX300 transaxles started failing prematurely since the drivers could not know, nor even so quickly change, adapt to, the new upshift technique.

Toyota's answer....

"Depress the gas pedal S..l...o...w....l...y for quick (QUICK???) acceleration.

In other words give the engine time to rev up slightly thereby raising the ATF pumping volume before reaching the pedal position wherein the ECU "realizes" a downshift is required.

Sure.

The drivers continued to think that when they pushed the gas pedal to the floor the transaxle should instantly downshift and GO...!!

Well, at least the engine (no DBW, yet!) responded quickly with HIGH revs..and then evenually the transaxle downshifted and once the downshifted clutches stopped SLIPPING due to the already high engine RPM...

paterd

I am wondering if I should even try to have the dealer look at it, looks like nothing will help anyway!

njguy70

Honestly, I don't know if it is worth it. I have an 06 4WD V6 and have had the delay since day 1. Initially I figured it was in the design. While it has been annoying at times, its really the only problem I have noticed and its nothing more than an annoyance. With the AC it gets a bit more noticible, but that is normal. If it is only a second or so and doesn't really happen all the time, just dependent on driving conditions, I would leave it alone and adjust.

I have had too many vehicles in recent years and honestly, there is no perfect car, no better dealer and everything is a trade off. I personally like the issues with my Toyota's better than the issues and hardships I had dealing with Honda.

Unless this becomes a major safety concern, which subjectively, it isn't, I wouldn't bother fighting the battle. Keep the relationship with your dealer for anything significant that may occur.

paterd

Funny you should say there is no perfect car, that's just what I've been looking for. Well, I had one once, a 1969 Chevelle convertible and after 20 years I sold it for a "more reliable" Subaru, which it was, but not nearly as much fun! I really thought the HIghlander sounded like the perfect car, reliable, etc. My sister has a 4 Runner, and it's been really reliable, albeit it rides like a truck, which I don't want, that's why I got a Highlander. A friend of mine has a 2002 Highlander, she doesn't have any problems, she loves hers. Guess they made the change after 2002.

lucky_777

You should check out new 2008 HL. It's been out for a couple of months but not a single complain from owners yet.

paterd

I had planned on trading up for a new model in a year or two. We'll see if the 2008 continues to be complaint free, maybe they made a change, let's hope so!

wc1

I have a 2008 HL 2WD and I have noticed a very annoying problem from day 1. When totally removing my foot from the gas and attempting to coast, the engine itself seems to brake the vehicle. I've watched the tach and it doesn't appear to upshift, but the "engine braking" is noticeable and very annoying. Does anyone else notice this?

aerosnow

I have the same "functionality" in my 08 limited. It was like that on all three 08's i drive. I assumed it was like that. No upshifting or downshifting. Tach remained the same. THis is pretty much when i drive slower than 25, but anything above 25, i really dont notice this "functionality". Lets see what others say.

paterd

A question for the 2008 Highlander owners, have you noticed the hestitation problem that I am having with my 2005?
Thanks,
Pat

lucky_777

easy fix for your problem

toyseeker, "2008 Toyota Highlander" #1708, 10 Oct 2007 12:26 pm

my_mr2

I have a 2005 FWD V6, with the updated transmission calibration TSB TC004-05. The calibration seems to help, but I found that shutting off the traction control(button on lower right side of steering wheel)a few times a month help in reducing the lag time. Another thing I found that helps a lot is using non-reformulated gas. I guess the computer senses more BTUs and adjusts the valve timing, spark timing, fuel injection, and shift points. I also notice 27MPG Hwy vs. 24MPG Hwy with the 10% Ethanol.

Hope that helps,
Mike

kenlw

..welcome to the wonderful world of bad science, Mike. Ethanol gives you less power, worse mileage and pollutes more, all while costing you more. Such a deal, right?

And as we divert more corn to bad fuel, corn, corn sweeteners, corn meal, tortillas, and anything that uses or eats corn, like cattle, therefore milk, meat, etc...costs more.

ain't ethanol great? Reformulated? some of use don't have a choice.

my_mr2

Did anyone try shutting off the traction control(button on lower right side of steering wheel)a few times a month? It help in reducing the lag time between shifts, and offsets what the computer learns.

Let me know if it work for your vehicle.

Thanks,
Mike

lucky_777

I don't really have hesitation problem on 2008 HL. Computer designed to learn driver's driving habits for a reason why disable this functionality?

paterd

That's interesting. I'm going to try that and I'll post the results. Thanks.

paterd

I checked for the traction control button and found out it is only on the 2 wheel drive models. So, guess I can't try that as a fix. Thanks anyway for your suggestion.