OK, one more question. Anyone else unhappy with the 2011 Highlander throttle response? I find that from a standstill, the throttle response is a bit vague, followed by a hesitation. I can get used to it but it is mildly annoying. I'm still experimenting but it seems like it might be the ECU reducing the throttle prior to shifting from 1 to 2 (which happens very soon after initial throttle application). After that point, the throttle response is fairly crisp. I don't recall noticing it during test drives but they were not in this particular vehicle.

I'm waiting for the vehicle to "learn" how I drive and adjust but so far, 1000 miles and nothing has changed.

Paul

Wow... Coming from an '01 Limited my '11 SE is just the opposite. The throttle response is a hair trigger. It's a bit tough to not take off like a jack rabbit. I'm getting used to the throttle but I can see where starting out in snowing conditions would be more of a challenge. My vehicle has 800 miles on it.

 

I should clarify.... if I get on it just a bit more than usual, yes it is very quick on the throttle response. Quicker than I'm used to. That also moves the shift point upwards in RPM, which tends to mask the "hesitation" as the ECU prepares to shift. But if I drive conservatively with gentle smooth starts, the first to second shift point occurs just after the vehicle starts moving and the resulting drop in throttle (assumed) makes it feel as if the engine was normally aspirated and lean... burst of power, then a drop, then it comes back and off you go.

Overall, I guess I would agree with you, the throttle is more responsive than I'm used to. Maybe that is part of the issue... I feel it respond with more power than I'm used to for a given pedal travel so I back off a bit. And that only magnifies the hesitation.

Paul

 

My '11 HL (1700 miles) is all smooth power, no hitch in the curve. Still getting used to the quick response after my 4cyl. vehicles.

 

I'm waiting for the vehicle to "learn" how I drive and adjust but so far, 1000 miles and nothing has changed.

If you haven't reset the ECU since the time of purchase then it's still using the shift points it learned the first 100 miles or so it was driven, which is typically when monkeys from the dealership drove it like Maria Andretti to gas it up and such. :ugh3: Reset the ECU and have it relearn your shift points again.

 

So it learns early and then not after that? It was driven about 200 miles (mostly freeway) to get it to me and it has been like this since it was delivered. How do I reset the ECU, disconnect the battery? What else do I lose doing that? The radio presets are OK. Anything else annoying? And while we're at it, if I had changed the customization (I have not yet) would that be lost?

Paul

 

Correct. I don't remember the exact number but it's 100 miles or so plus or minus. Yep, disconnect the battery. You'll lose your radio and clock settings, but that's a minor thing considering what you gain. When I first got my HL my mileage sucked after a couple of times it was driven by dealership staff (including to gas it up), and after I reset the ECU my mileage jumped up and my shift points were improved as well. Don't know about customization being lost as I've got a Base model without any bells and whistles...hopefully one of the Sport or Limited owners can answer that question for you. :thumbsup:

 

Mine is a base model 2011 (with tech package) too. I have not paid for any customization.... just wondering if it would be lost if I did the battery disconnect. I'll do the reset tomorrow morning and see what happens. That would explain why I never noticed it on test drives. I'll be really pi$$ed if my MPG drops though I'm getting 23MPG on my commute. That is compared to 19.5 with my previous vehicle (2002 Buick Rendezvous) on the same route. And I thought the Buick was good!

Thanks for the speedy answer and for this forum, full of to-the-point answers without "attitude". Rare these days!

Paul

 

Paul, if you're a mellow driver I don't see why your mileage shouldn't at least stay the same or even increase. Average your results over four or five tanks of gas and report what you find. :thumbsup:

 

OK, reset performed. On the first drive cycle (cold to hot), it does seem better. Maybe even gone. Hard to tell since there weren't a lot of stops and starts and the idle was not down to normal yet. I did notice that on the first start, it died right after it started. The second one was normal. The idle was higher than usual during the drive, and that might have masked the original problem. When I parked it I left it running in park for a while and the idle slowly ramped down to the usual ~600RPM and stayed there when I put it in gear, so it was clearly learning something.

I'll let it cool and then repeat and see how it behaves.

MPG was very low at the beginning but that could also have been that it was not warmed up. It seemed to return to normal during the drive. I'll be real curious to see if it ends up better than it was. That would be quite a feat, though, since it was VERY good to start with. This is a 2WD V6 and it was running 23MPG on my 20 mile commute in some stop and go and mostly 45MPH limited stoplight traffic. As I posted above, the vehicle the Highlander replaced (2002 Rendezvous) got 19.5 on the same commute and I thought THAT was pretty good

Note for future reference that I DID NOT lose the radio presets after the reset but I did lose the clock and historical MPG data. The battery was disconnected for about 20 minutes.

Paul

 

OK, update. After driving for a while, the throttle "hesitation" seems better but it is not completely resolved. What is more clear now is that it definitely is caused by the vehicle backing off the throttle during the shift from 1st gear to 2nd. Since the shift takes several seconds and the throttle reduction is more than what would be required to maintain a constant acceleration through the shift, this causes a noticeable drop in acceleration without me moving the accelerator pedal. It keeps subliminally triggering my "engine is lean" detectors. I guess it is just an artifact of computer control and drive by wire? I'm getting used to it but it just doesn't "feel" right. I wish I could trim the throttle behavior during the shift.

Paul

 

Here are links to two past threads discussing the transmission lag/hesitation you mentioned. They may provide additional insight. BTW, I'll add this subject in the Common Problems & Solutions sticky for future reference by members.

http://www.toyotanation.com/forum/showthread.php?t=365788

http://www.toyotanation.com/forum/showthread.php?t=262909

 

Thanks for the links. It didn't occur to me to search since I couldn't figure out what to search for

I tend to accelerate gently and smoothly most of the time. That seems to accentuate the 1st to 2nd shift hesitation. I'm getting used to it and at least it doesn't bother me as much now that I know what it is.... and what it isn't.

Are you sure the HL starts in 2nd in drive? What would cause it to use 1st? Only a manual shift?

Paul

 

Pull the shifter to +/- (pull towards yourself), the gear indicator will show "S". Then pull the shifter on "-" once, it will show S2 (2nd) --> pull once more it will show "S1" (1st). Once you try S1 you will see the car always start with 2nd in "D" unless you're on a very steep hill .

 

Thanks, I see what you mean.

Here's a MPG update after the reset and several drive cycles. I drove about 16 miles round trip, about 80-90 percent freeway (75MPH), windows up, no AC. I reset the computer once I was on the freeway (ie., this did not include the warmup) and for the next 8 miles, it averaged 29.7MPG at 75MPH. Yikes, that is good! I thought it was going to break 30 but it didn't. The round trip (including a small amount if idling at a couple stoplights) averaged 27.5MPG. I can't say for sure if that is better than it was pre-reset, but it sure isn't worse. And in my opinion, VERY impressive for a vehicle this size that can tow 5000 pounds. THAT is why I balked at a really pretty used red GMC Acadia..... it can't touch that mileage with a stick and the HL can tow 500 pounds more

Paul

 

OK, it has been about 400 miles since I reset the ECU to attempt to resolve the throttle response delay. The first 100 miles or so, there was a very small improvement but the engine still de-throttled excessively during the first shift. The shift duration still seemed abnormally long.

However, it is now about 400 miles since reset and things definitely have changed for the better. The de-throttling is now almost unnoticeable and the shift duration has become much shorter. Taken together, and the throttle response from a dead stop is now what I would loosely call "normal". I didn't notice when it changed... it might have been incremental over the last couple hundred miles.

Paul

 

Some additional (longish) thoughts and *possible* fix to the throttle response/throttle tip-in issue...

My wife was *very* exasperated about her '08 HL yesterday, to the point of wanting to trade me cars for a while. After hearing about the jumpy throttle from her for some months, I began to analyze the issue in earnest.

* I know that the drive train is a modern learning type; meaning it will change its shift points and (probably) throttle response according to drive habits. The more agressive you are with the throttle, including quick throttle movements, it definitely responds by grabbing lower gears faster and holding onto gears longer.

* It would appear--maybe my imagination--that the throttle response also gets more aggressive. It has throttle-by-wire (TBW), so this is certainly among the programmable/mappable parameters. Any Toy techs on the forum?

* I also noticed--and this seems key--that the accelerator pedal resistance (spring pressure) is considerably less than my '02 HL. I've had trouble holding steady speeds on the freeway unless I concentrate. It also allows faster than may be typical tip-in, which may be signaling "aggressive" to the drivetrain?

So, it occurred to me that my wife, who sort of stabs at the throttle anyway, combined with low spring tension, combined with throttle by wire and an adaptive drive train, all conspire to making the truck "jumpy". It also seems to correlate to the truck's tendency to be a bit confused when rounding a corner, where you lift off the throttle then reapply.

After closer scrutiny, I think it is just in 2nd (or 3rd?) during the lift off, and then a stab of the throttle causes a downshift to 1st, but being TBW, it holds off on opening the throttle until the shift completes. For gentler right feet, the tranny may be in a much less aggressive mapping, where it doesn't grab 1st stays in 2nd, thus no shift delay and no lurching.

I sort of tested this theory by putting the tranny in "Snow" mode which prevents 1st gear downshifts and does launches in 2nd. Very smooth. All this is probably obvious to many of you, but it's the first time I've pondered the issue.

The conlcusion was that increased pedal tension would reduce the effect of a twitchy foot and maybe allow the drive train to unlearn some aggressive mapping.

My experiment began by removing the accelerator (2 nuts, 5 minutes), put it on then bench and see what could be done to increase pedal resistance.

My pedal has 4 torx screws holding the clam shell together. Inside are two coil springs; a larger one about 19mm in diameter and a smaller ~15mm diameter coil spring inside the larger. It appears the springs are color coded and possibly selected at the factory for some target force.

The springs and pedal lever just pop out. The springs were 6cm long. I gently stretched both to about 7.5 cm, re-assembled the springs and popped them back into place, put the clameshell back together and bolted the pedal back to the car. 20 minutes start to finish.

Since we have a 40 min long drive to church with lots of stop signs and lights it seemed a good test, where the drivetrain might partially relearn and test the "fix". I drove there and immediately noticed the increased pedal resistance by itself made it was easier to modulate smoother launches, not to mention *much* improved speed management on the freeway.

I told the wife about the mod on way back home 3 hrs later and asked her drive home. I chatted her up to distract for the next 40 min to keep her from concentrating on being smooth. It may be my imagination, but the truck seemed to get smoother in stop and go as we drove. She seemed to think it was better as well, not to mentioned I noticed much less lurching from the passenger seat.

The next week will be telling; whether the increased tension keeps her from being able to stab the throttle as much and whether the drivetrain relaxes in response.

If the fix seems a good one, I'll post photos I took of modifying the pedal.

 

Interesting. In addition to the shift issue I described in my OP, I too found the throttle and the brakes to be a lot more sensitive than I was used to (my previous car was a Buick Rendezvous). However, I took the simpler approach.... I just waited. Eventually, my HL and I got used to each other. I am now, 10,000 miles later, completely used to the throttle and brake response and have no issues with either. I assume the ECU has also gotten used to me, and possibly adjusted the throttle curve. Or not.

Paul

 

After 6000 miles, she's running out of patience, and frankly I don't think her foot is going to get any calmer. After driving my 02 for a week, it takes me 10 min to get the hang of the 08 throttle, although it takes concentration to be smooth. Disappointed Toy doesn't acknowledge the issue.

Glad you eventually adapted.

 

After a few weeks of driving by both my wife and me, I can say that raising the pedal tension from around 2.5lb to around 3.8lb made a significant difference in jumpy starts and slow-for-corner lags. We drove for 3 hrs yesterday house hunting with her driving most of that. I didn't notice one jumpy incident.

Now, whether the increased tension just dampened her overactive right foot and/or the transmission and throttle have relearned for a less aggressive response, don't know.

I tend to think both.

One other thing that confirmed my suspicion that she applied the right foot more aggressively was her complaining yesterday of the VSC light coming on when taking off at stop lights, where it was like someone had the brakes on. I drove later that day and asked her what she did--said she just pressed the brake. I finally duplicated the behavior by stepping pretty hard on the brake pedal--much harder that I'd brake except in a panic.

I just learned this evening after browsing the 2nd gen FAQ's (very handy Trail D) that this is how "hill assist" works. :facepalm: The woman will not be amused that this is "normal"....