My theory on the 07 tranny hesitation problem

[Klutch]

I have a 5 speed but I believe mine has a hestitation as well, especially in 2nd gear. My theory for the problem is as follows (especially for you auto owners).


I believe the fuel mapping is off in the cars and needs a new ECU program because it's starving for fuel. I do however believe that the hold-up on them doing anything about it is a very simple one. First off they don't want to jump the gun, they're still gathering data to try to make sure the update is good for everyone. Secondly, I believe they'll have to carefully watch how the new programming affects the fuel mileage in the cars. Since it would be tinkering with the fuel consumption they'll have to have the EPA scrutinize the update to make sure they can still sell the car with the as advertised fuel mileage.

I have no evidence to support what I type here, this is simply my thinking on the matter.

[Epsilon]

You can try proving your theory by getting your car dynoed and tuned. This way you can determine where the hesitation is, the reason behind it, and how it can be fixed.

[rollon1300]

Klutch,

Thanks very much for your post. I was just thinking of asking if there were any 5-speed manual owners out there having the hesitation problem - and you posted this.

When I first posted about this problem, I had already had a Toyota engineer from the factory ride with me with a scan-tool and he confirmed and recorded lean conditions during application of the throttle. This diagnostic ride occurred in early June and, to this date, there has been no release of a fix - at least to my knowledge.

By the way, I recently posted a message on the Edmund's 2007 Camry Woes forum detailing my comparison of two new '07 Camry's, one PZEV and one ULEV, compared to my '07 PZEV. They were all 4-cyl 5AT vehicles. The hesitation problem shows itself on all three, but it varies from car to car. This makes for a vehicle that, in a few ways, verges on being unsafe to the occupant/s and a menace to other drivers.

[BigWillie]

I have the same problem with my 07 LE 4 cyl. From a start or low speeds, there is a hesitation with the throttle. I go thru the tolls here in NH using EZ pass and you gotta pass thru them going no more than 25 MPH. Once I go thru, I step on the gas and there's nothing! I'm afraid one of these days someone's gonna rear end me! I'm pretty sure I nearly floored it to get moving, but then that's not good doing that. I swear there's no middle ground with the accelerater, either you are crawling or you gotta floor it. Cruise control, forget it, I hit a small incline and the car drops a gear and I'm at 3600-4200 PRM. My wife's 2001 Hyundai Elantra performs better than my car. I never should have traded in my 03 Tundra for the Camry, but a growing family and rising gas prices left me no choice!

BigWillie

[LunarMist]

There are no theory's to prove unless the thread starter is talking about a different problem. The issue concerning the hesitation on 07 Camry's has been addressed and solved (as far as why its happening) weeks ago when I posted a thread about it and also when others posted similar information. I suggest doing a search. The hestitation of the 07 Camry is caused by the cars "drive-by-wire" system. Do and internet search or a search on TN and you will find plenty of info.

[RockXP]

[anitelite]

I've noticed now that when I sit at a light with the brake applied, that about half way through the wait, the car seems to shift into gear and want to move forward. If I don't have my foot firmly on the brake, it will actually move forward a bit until i really mash on the brake pedal.

As to the poster who is complaining about all this hesitation and drive by wire as old business, I just want to point out that
a) it aint been fixed yet
b) it is at very best a safety defect
c) it spoils what otherwise would be a relatively ok car

so...no it isnt' going to get shoved under the rug until there's an honest fix for. get ready cause i expect there's going to be more and more noise about this.

[slim_EL]

I would question the "drive-by-wire" theory being related to hesitation because so far I have had absolutely NO hesitation issues.

Having read all about the "hesitation" reviews prior to my purchase, this was my # 1 concern when buying this car.

I have a 4cyl. 5AT SE, build date 6/24/06 with 1700km's and counting... So far it doesn't hesitate at all.

I have tested it with both hot/cold engine conditions;

- off the line(light) - accelerates immediately (from 0km/h)
- rolling start - push the pedal and it drops the gear instantly and accelerates (10-20km/h)
- passing on the hiway (100km/h +)
- merging into trafic (30-60km/h)

I hope Toyota can figure it out for those who are having these issues.

I do have rattling problems however... but i'll take those over the hesitation anyday...

[LunarMist]

Originally Posted by anitelite

I've noticed now that when I sit at a light with the brake applied, that about half way through the wait, the car seems to shift into gear and want to move forward. If I don't have my foot firmly on the brake, it will actually move forward a bit until i really mash on the brake pedal.

As to the poster who is complaining about all this hesitation and drive by wire as old business, I just want to point out that
a) it aint been fixed yet
b) it is at very best a safety defect
c) it spoils what otherwise would be a relatively ok car

so...no it isnt' going to get shoved under the rug until there's an honest fix for. get ready cause i expect there's going to be more and more noise about this.

Sigh, this is an issue that ALL vehicle manufacturers who are switching to "drive-by-wire" will be encountering. This isn't something that is going to take a simple twist of the knob to alleviate. Until someone comes out with another more advanced version of this system, every automaker who incorporates this technology into their vehicle line-up will be experiencing this. Its just something that comes with an intelligent drive system that as of now can't really be altered. Again, if you would do some simple research, you would find answers to this. Somebody posted a direct link to a well written document which described drive-by-wire in detail and it specifically stated that the next time you are in a new car and you experience a resistance for your car to want to respond to your commands, its probably the drive-by-wire system.

[LunarMist]

Originally Posted by slim_EL

I would question the "drive-by-wire" theory being related to hesitation because so far I have had absolutely NO hesitation issues.

Having read all about the "hesitation" reviews prior to my purchase, this was my # 1 concern when buying this car.

I have a 4cyl. 5AT SE, build date 6/24/06 with 1700km's and counting... So far it doesn't hesitate at all.

I have tested it with both hot/cold engine conditions;

- off the line(light) - accelerates immediately (from 0km/h)
- rolling start - push the pedal and it drops the gear instantly and accelerates (10-20km/h)
- passing on the hiway (100km/h +)
- merging into trafic (30-60km/h)

I hope Toyota can figure it out for those who are having these issues.

I do have rattling problems however... but i'll take those over the hesitation anyday...

^^^^ Read the above response ^^^^

[slim_EL]

Lunarmist - I don't know what you're referring me to by saying:

^^^^^read the above response^^^^^

.... since my car does NOT have any hesitation problems so far.

[LunarMist]

Originally Posted by slim_EL

Lunarmist - I don't know what you're referring me to by saying:

^^^^^read the above response^^^^^

.... since my car does NOT have any hesitation problems so far.

Because you stated:

"I would question the "drive-by-wire" theory being related to hesitation because so far I have had absolutely NO hesitation issues."

So my response to the other fellow was also addressing you in a way.

[Klutch]

The "drive by wire" excuse is a load of shit being spoonfed by Toyota. Plenty of manufacturers have implemented drive by wire with total success, this is a programming issue which at the end of the day is all linked together.

My car is a manual by the way, the only hesitation I have is in 2nd gear until I hit about 3200-3500 RPM's.

[LunarMist]

Originally Posted by Klutch

The "drive by wire" excuse is a load of shit being spoonfed by Toyota. Plenty of manufacturers have implemented drive by wire with total success, this is a programming issue which at the end of the day is all linked together.

My car is a manual by the way, the only hesitation I have is in 2nd gear until I hit about 3200-3500 RPM's.

This is true but you would have to image that so far (as far as I know) the only manufacturers who have been using drive-by-wire are the European luxury brands. Drive-by-Wire is only now starting to trickle down to the non-luxury segment where there is little or no experience. It's not an excuse because Toyota should have gotten this right or not did it at all but it could be a small explanation.

And actually in Toyota's defense, I've never read an article where Toyota actually addressed this issue or tried to use drive-by-wire as a scapegoat. Thats part of the reason why people are playing so many guessing games because Toyota hasn't actually specifically referenced drive-by-wire.

[G.F.K]

Originally Posted by Klutch

The "drive by wire" excuse is a load of shit being spoonfed by Toyota. Plenty of manufacturers have implemented drive by wire with total success, this is a programming issue which at the end of the day is all linked together.

My car is a manual by the way, the only hesitation I have is in 2nd gear until I hit about 3200-3500 RPM's.

to give you a little background i workas a tech for a bmw dealership.and ever since the introduction of the m52 tu motor in late 99(if i remember correctly) there is constant (annoying at best but slight) issues with "drive by wire" even on "all" the new models theres still problems with engine-trans-throttle meshing correctly all the time.theres programing fixes and sib's out the ying yang.but still issues persist.ive never owned a "new" toyota but if itis an issue im sure the engineering dept is trying to figure out a fix as we speak.the car is still new.these things happen every once in a while.