Transmission Hesitation 08 HL Sport ........ Is this normal? - Toyota Nation Forum : Toyota Car and Truck Forums

formularob · 12-09-2010, 09:53 PM

I have an 08 Highlander Sport 4WD. It seems to me that the transmission has a lag when coasting and then accelerating. I am not driving aggressively. This is very noticeable when coasting around corners at residential speeds and then applying the gas, the transmission appears to not know what to do. It’s almost as if it needs to downshift and then it catches and takes off, the engine revs up a bit and then it catches, This is also very noticeable when slowing down and coasting over speed bumps at a mall, when you come off the speed bumps and apply the gas the same thing happens. Other than this the vehicle is great, on the highway it sounds fine and shifts what I would describe as normally. I have been to the dealer with this several times, The technician has been out with me and has seen what I am talking about, he suggested the computer that controls the shifting had learned the previous owners driving pattern and it should be reset. This was done and I think maybe it got a little better but now after 6 months it seems worse than ever. I had it back to the dealer 2 months ago and the service manager drove it and got it to do the same thing. He then took a used 08 Sport they had on the lot for a drive and said it did the same thing. He told me he spoke to Toyota Canada and was told that this is normal and has suggested to me there is nothing wrong with this, he has acknowledged to me what it does and has told me that is just the way it is. If Toyota come up with a computer program upgrade maybe it could be fixed otherwise there is nothing they can do. I have spoken to Toyota Canada and they simply went back to the service manager who has already figured it all out and they tell me there is nothing wrong with it and what it is doing is normal. I know there are many 08 Highlander Sport owners on here. Can someone tell me if this is normal? Sorry for the long winded explanation however my warranty is just about up and If there is really something wrong with this I want it fixed now while there is still time. I welcome and thank all for your comments.

***summerwind*** · 12-10-2010, 06:25 AM

Mine does it also.
When you coast the fuel management system temporarily shuts off the injectors. There can be a slight lag while all the computer stuff figures out what to do next. Read the attachment on how the injectors work . It also explains why when the engine is cold it sounds like a diesel when you step on it.

How the fuel injectors work

***TrailDust*** · 12-10-2010, 10:48 AM

We also have a past thread in here that you'll want to use the forum's search feature to locate, which discusses the "transmission lag" thing at length. When someone or myself locates that thread I'll post up a new entry to the Common Problems & Solutions sticky since it's a common enough issue and worthy of posting. BTW, I experience it too, and like summerwind said I always attributed it to the computer system running the vehicle and having a brain fart under the conditions you described. I've never found it too bothersome myself.

EDIT: Here is one of the threads I had mentioned...click here. Let us know if that's what you're experiencing.

naturoses · 12-10-2010, 07:25 PM

Hi Summerwind and Traildust, I was about to post this question which I have been experiencing more recently in residential area driving. I have 3000 miles on my car and I was wondering and worried thinking about this happening to my car suddenly. At highway speeds, I do not observe this lag at all. In city driving, this lag is so much that sometimes it feel that my car just takes off like that with any hesitation after few seconds.... I am glad this is normal and saved me a trip to the dealer....

formularob · 12-10-2010, 08:07 PM

Thanks very much guys, although I'm not real excited about this feature I am glad to hear that this is normal and not a ticking time bomb. Thanks again.

Yazon · 12-10-2010, 08:46 PM

I've had the same, so I've disconnected the battery and reconnected it back in a few minutes and now the tranny is much smoother.

nov0798 · 12-11-2010, 04:36 PM

I also have an 08 Sport that does the same thing.

I would have to argue the fuel injector thing, and say its a dead spot in the transmission programming map thats loaded into the computer, but who knows?

BUT, on the fuel thing, I had a Mercedes that had a rough time accelerating through a certain part of the rpm range, and a flash with the german fuel map for that particular car fixed the problem. I know it was fuel because it had a manual tranny.

This is irritating, and I think Toyota should look into it and fix it. Just wondering if any 09 or 10 owners have the issue? Maybe Toyota flashed their computers with a different program.

mikmabz · 12-11-2010, 06:14 PM

I have a 2009 Sport (Japan) and I am not experiencing that "lag" thing.

Dman1 · 12-11-2010, 08:06 PM

2009 Limited made in Japan and yes, I experience it too.

naturoses · 12-11-2010, 08:57 PM

Mine is 2010 SE, and I experience it now (from around 3000 miles)

***TrailDust*** · 12-12-2010, 01:20 AM

Quote:

Originally Posted by Yazon

I've had the same, so I've disconnected the battery and reconnected it back in a few minutes and now the tranny is much smoother.

I'd tend to agree with Yazon that resetting the ECU can alleviate some of the problem. When I first got my Highlander after some of the dealership gorillas had finished driving it to gas it up, check ride, etc., it did the lag thing big time. I unhooked the battery and reset the ECU, then drove it like I normally do an the change was significant. Nowadays the only time I really experience it is when I'm about 30 to 50 MPH, take my foot off the gas and coast for just a half second or so, and then hit the gas pretty hard (like when trying to make a light that's just turned yellow). Most of the time it's not an issue.

littleslim1474 · 12-12-2010, 06:02 PM

Yes this is very normal for this trans, the trans learns your driving habbits, if your just cruising (45mph) the trans is probably in 5 gear (overdrive) and if you go and give it alot of gas the ECU go oh he wants to go faster now, the ecu downshift the the tranny to 3rd gear which is that lag your seeing. when you disconnect your battery the computer learns some of the learn values and go back to factory and starts to relearn your driving habits again. If you drive your HL hard during this period you'll see it will learn to shift quicker and harder.

AVConsult · 08-02-2011, 12:57 PM

bumping this thread again....

Just acquired a 2008 HL Base. The off/on throttle thing at neighborhood speeds is getting very annoying. My wife also complains that she has trouble avoiding jack rabbit starts--i.e. tip-in is very touchy.

I tried the disconnect-the-battery trick, which helped the transmission issue "slightly* and only for about a week.

Has anyone ever taken their HL into a dealer and specifically asked about any ECU updates that address this?

***becks*** · 08-02-2011, 02:32 PM

I had the same problem as everyone above experiences. Since removing the charcoal filter I have not experienced it. I always called it lag but, "brain Fart" works too.

Here is the thread:

Removal of Charcoal Filter from Air Box

***sweeneyp*** · 08-02-2011, 05:06 PM

Quote:

Originally Posted by AVConsult

bumping this thread again....

Just acquired a 2008 HL Base. The off/on throttle thing at neighborhood speeds is getting very annoying. My wife also complains that she has trouble avoiding jack rabbit starts--i.e. tip-in is very touchy.

I tried the disconnect-the-battery trick, which helped the transmission issue "slightly* and only for about a week.

Has anyone ever taken their HL into a dealer and specifically asked about any ECU updates that address this?

I don't mean to sound harsh so if it sounds that way, im not. If you reset the transmission and it improved, only to return to normal, then it probably means one of yall are probably driving it accelerating a little harder than normal. Otherwise the transmission wouldn't relearn that more "aggressive" throttle response pattern. One way to figure that out is, what kind of mpg are you getting because if you are getting 15-16-maybe 17'ish i'd say you probably are pushin it a little during acceleration, if you were getting higher then it might just be a ECU issue. I had heard that when they re-flashed the ECU during the pedal recall they made the throttle less responsive, but I'm not certain about that. Mine will jump like that if I've been coasting (at like 30ish) and quickly get into the throttle, but if I ease into it the transmission works fine. Now it could be just the fuel injectors shutting off while coasting (no gas pedal at all) to save fuel, you get into the throttle and that feeling is the engine "refiring" if that makes sense, but that is a total guess