How Do You Keep An Auto Trans In The Highest Gear?

[bronsin]

Or: what is the slowest speed you can go in a Yaris and still be in 4th? I ask because I may be driving in remote sections of Canada this summer where roads are bad and fuel infrequent. I will need to maximize fuel economy at times.

Thanks!

[staticorex]

Your manual tells you that max speed you can be in before having to shift up. I believe it says 85mph before you have to be in 4th. But I haven't checked it in over a year and my memory is terrible. You should be able to look it up in your manual.

As for the slowest, My Nissan Rouge lets me shift manually and I can shift up to 6th gear at VERY low speeds. I think I was driving around 25-30mph in 6th the other day. But that's a cvt transmission. I'm not sure if it's the same.

Hope that helps you somehow.

[Tonavi]

I think you just have to be really gentle with it. My 1991 Acura Legend went in 4th at 25 MPH if I was really gentle.

[BIGTAZ351]

If I'm easy on the gas pedal 30-35, the car seems to get the best mpgs at about 45 mph. Get a scangauge2 its worth the money! RPM's, instant MPG, Avg mpg, and much more at the press of a button.

[rick996]

I recommend the Scanguage II too. Besides helping you drive more efficiently, it gives you a pretty good estimate of the gas left in the tank and how many miles you can go on it using current conditions.

[R2D2]

Bronsin,

The Yaris wants to hold 4th for dear life! It will do so for as long as possible and is more dependent on load than speed. When cresting a hill you can back out of the throttle gradually and keep the load low enough to avoid a shift. When it does decide to shift it needs to and is saving fuel! Fantastic auto trans IMO.

R2

[bronsin]

Hmm interesting. That is some valuble advice. The main thing I DONT like about it is its insane programming to remain in thrid until the cool blue light goes out. A manual you can shift into 5th at 35 on a level ground immediately.

[R2D2]

Yep. You've got that right. I'm glad I don't immediately have to get on a highway on cold mornings-that would really be a bummer! I really hate having to rev a cold engine above about 1500 rpm.

I wonder if CTScott knows how to engineer a fix for the 4th gear lock out?

[bronsin]

I wonder if CTScott knows how to engineer a fix for the 4th gear lock out?

Oh PLEASE PLEASE PLEASE!

[CTScott]

It would just be a matter of switching a resistor in parallel with the engine coolant temperature sensor. The ECM sees a dead short as 140C and a full open as 40C, so it would just be a matter of selecting the correct resistor value to put it in the normal warm range. I am packing to head out of the country tomorrow morning, but I'll do some experimentation when I return.

[bronsin]

It would just be a matter of switching a resistor in parallel with the engine coolant temperature sensor. The ECM sees a dead short as 140C and a full open as 40C, so it would just be a matter of selecting the correct resistor value to put it in the normal warm range. I am packing to head out of the country tomorrow morning, but I'll do some experimentation when I return.

:headbang::headbang::headbang::headbang::headbang: :headbang::headbang:

:thumbup::thumbup::thumbup::thumbup::thumbup::thum bup::thumbup::thumbup:

:w00t::w00t::w00t::w00t::w00t::w00t::w00t::w00t::w 00t::w00t::w00t:

:bow::bow::bow::bow::bow::bow::bow::bow::bow::bow: :bow::bow::bow:


If this works it will be so awesome!


Maybe you should postpone your trip and get started working on it right away? :evil:

[Kal-El]

Bronson, considering you opened two threads about the auto not doing what you want, it looks like you should've bought a manual. :tongue:

[DebbyM46227]

I drive a manual, but I still don't go above 40 MPH until my cool light goes off, and in the winter when it's really cold outside, it can be 3 or 4 miles before the engine warms up enough for it to go off.

There's a reason Toyota did this, they didn't set up the automatics this way just to tick you off.

[bronsin]

Bronson, considering you opened two threads about the auto not doing what you want, it looks like you should've bought a manual. :tongue:

I never would have but my feet are numb and get painfull pushing in a clutch. Had to go auto.

Say do they make a hand clutch adapter for handicapped people? I would be so there.

[bronsin]

I drive a manual, but I still don't go above 40 MPH until my cool light goes off, and in the winter when it's really cold outside, it can be 3 or 4 miles before the engine warms up enough for it to go off.

There's a reason Toyota did this, they didn't set up the automatics this way just to tick you off.

And the reason is...THEY ARE MORONS! I work with engineers all the time and you would not BELIEVE the insane things that get in their heads sometimes.

Im thinking this mod is going to be as big as the cruise control one!

CANT WAIT

:thumbsup:


Deb you are an ENABLER! :bellyroll:

[sbergman27]

I wonder what other effects might result from tricking the ECU into thinking that the coolant is always warmer than it is.

Sounds like a bad idea to me.

I'm not that familiar with the Yaris' control systems, or what is controlled by the ECU and what is handled by discrete systems, but...

Any strategies that the ECU uses to optimize fuel economy and driveability during warm up would likely be thrown off. And at normal operating temperature, the radiator fan might run continuously. (Or is that independent of the ECU?) And the ECU might go into emergency measures (timing advance? idle speed increase?) to control the "overheating" situation it erroneously detects.

Rather than messing with the ECU's sensor inputs, I think I would be more inclined to investigate the rationale behind the temp lockouts in the first place. I suspect they are there for a good reasons which we might agree with if we knew exactly what they were.

If the engineers who wrote the control software are "morons", I'm not quite sure what to call the person who messes with fundamental sensor inputs, like coolant temperature, without taking some time to think very carefully about the possible repercussions.

-Steve

[bronsin]

Maunal transmissions can be shifted into 5th at any time after starting the engine. Are THEY having problems because of that? If they are they are keeping very quiet about it. No of course they are not! Eveerything is just fine! Now...is it possible the..er...GENIUSES who designed the software for the ECM have made such a rats nest of it that messing with the sensors will ball everything up? Why of course! We have to be carefull. But maybe there is another way to make the transmission shift into high just like the its manual brother can. I dont know.

Let me tell you something about engineers and scientests. They are IDIOTS just like everybody else. They invented the ATOMIC BOMB for Gods sake thinking it was a great thing! Was THAT a good idea? Are you you happy living in a world that could be blown to bits, thanks to them? I hope the answer is NO! Well there, are you going to let these people tell you what to do? Tell you how to live your life? Fall at their feet and worship them and eat their shit? Well good for you! I will pass on that one thankyou very much! I will do whatever I can! And if I want to try to make my auto trans shift into forth before YOURS does that is just too bad!

[yaris2010RS]

^^ o00o0o0o0o0o0o thread just got very interesting

[sbergman27]

Let me tell you something about engineers and scientests. They are IDIOTS just like...
Wow. Did an engineering student once steal your girlfriend or something? You may want to consider seeking help for this unhealthy obsession.

Using coolant temperature as a factor in adjusting the fuel map, ignition timing curve, or whatever, is hardly creating a "rat's nest". But you're certainly welcome to investigate your options for re-flashing the whole ECU with your own software image. Then you could set it so that only 4th and reverse were available.

You'd need the proper interface equipment and communications software. A decompiler, a compiler. Some knowledge of embedded programming. A firm grasp of the details of the Yaris' various systems. And also of the relevant legal codes for your country and province. I'd be daunted by the task, even though I'm a programmer. But you seem really smart, so I expect you'd have no trouble.

And surely *that* would be enough to get you from point A to point B on these fictitious... err... desolate Canadian roads where it takes every last drop in the Yaris' 11.2 gallon tank to get you from one gas station to the next.

But first, you might want to verify that the existing transmission control algorithm is actually hurting, and not improving, overall fuel economy. You could enlist the help of someone with a 5 spd and a Scangauge II to do some preliminary testing. Not a perfect simulation, to be sure, since it leaves the torque converter, among other things, out of the equation. But nonetheless, it would be interesting to see the results.

-Steve

[bronsin]

Wow. Did an engineering student once steal your girlfriend or something? .

-Steve

No. They were so imcompetant it nearly cost me my job.

[sbergman27]

No. They were so imcompetant it nearly cost me my job.
I'd suggest being careful when tempted to make wild generalizations.

At any rate, if you are serious about this, one thing you definitely should consider is a block heater. Why trick the ECU into thinking the engine is warm when you can actually make it so? With a good hefty one (say 1500W) you could either put it on a timer, if your schedule is predictable, or toggle it on a half hour before you leave the house.

Also, I'm quite serious about partnering with someone on the board to take some actual measurements of how fuel use varies with transmission shifting strategies during warm up. Also interesting would be engine wear info... which is not something that we're going to be able to do in a home-spun way.

Driveability and emissions requirements are other possible reasons for the lockouts. The more I think about it, the more "emissions" seems like a likely reason. I don't pretend to know the answers. But clearly, you want to have some understanding of the strategy you are modifying before you modify it.

In fact, when it comes to these kinds of things, the long-term educational aspects almost always outweigh any perceived short-term goals. For me, the short-term goals are usually just convenient motivators to make the game more exciting.

In my heyday in the 70s, I did a lot more fiddling with the 1968 Cadillac Fleetwood Brougham that I was forever trying to "upgrade" to compete with the 1976 Fleetwood, which I considered to be the bee's knees at the time. (Truth be known, I kinda still do.)

I learned a lot. But I ended up eventually ruining the car. (Though it took me 20 years to do it, and another 10 to realize that I had.) Fortunately, I had another... a twin... which had originally belonged to my father's business partner. And it survives to this day, though I don't drive it much, these days.

Anyway, the point is that there is much value in studying the theory, however much fun soldering in the mods might be.

And do be careful what you wish for. ;-)

-Steve

[bronsin]

I have a 700 watt hot plate I used to use under my 240D on cold mornings. Set on a timer to give a half hour burn before departure time, you could feel the warmth on the valve covers.

That would also have the effect of warming the engine much nearer to operating temps. Which could be very good!

[SAV912]

And the reason is...THEY ARE MORONS!

Yeah, right. A wild generalization based on some engineers you worked with in a category that had nothing to do with automobile manufacturing.

You know what would be a lot easier than creating a potential problem by programming an ATX to do something it wasn't intended to do? A block heater. Engine is warm upon start up, and you get your shift to 4th right away. Rest of the country in winter has this figured out, don't know why it's so difficult.

And as far as the best fuel economy, cruise control isn't the way to go either, yet you added that to your car. Maybe you'll get a little more respect with your answers to your threads after you stop painting an entire industry of people with one brush. Not all of us are the idiots you proclaim us to be because you had an incident with a select few several years ago.

To answer your question for this thread though, it's about 30 MPH, but it all depends on load. Drive as if there's an egg under the gas pedal, you'll be in 4th gear nearly all the time.

-C

[bronsin]

Well I would like my transmission in the highest possible gear as soon as possible. I seldom drive more than 6 or 7 miles at a time so every little bit helps. Doubly so now that they are putting mileage robbing alcohol in our gas and charging us $4 a gallon (and soon to be more?) for it. If I could drive a manual I would but I cant. I have no sensation in my feet and pushing in a clutch pedal (over time) makes it almost too painfull in my left foot to walk.

[sbergman27]

Doubly so now that they are putting mileage robbing alcohol in our gas and charging us $4 a gallon (and soon to be more?) for it.
Let's try to limit the misinformation. E10 fuel contains about 3% less energy than E0. And indeed, controlled testing generally shows a +1% to -4% change in fuel economy, with an average around -3%.

I'm not sure about Canada, but in the US E10 is generally about 3% (~11 cents/gal) cheaper. So the effective price is essentially equivalent.

-Steve

[jambo101]

Or: what is the slowest speed you can go in a Yaris and still be in 4th? I ask because I may be driving in remote sections of Canada this summer where roads are bad and fuel infrequent. I will need to maximize fuel economy at times.

Thanks!
I cant believe there are normal roads in Canada where a 700km range wont get you to a gas station.if you are worried about running out of gas just pack a red plastic 5gal gas tank for the long stretches..

[bronsin]

I cant believe there are normal roads in Canada where a 700km range wont get you to a gas station.if you are worried about running out of gas just pack a red plastic 5gal gas tank for the long stretches..

You are probably right BUT sometimes stations are closed or out of fuel. You dont take chances period. Or at least I dont. 30 years of flying airplanes and riding motorcycles makes me plan every move very seriously.

These roads arent normal though. They are the roads from Dawson to Inuvik and Fairbanks to Prudehoe Bay (Alaska I know)

[sbergman27]

I cant believe there are normal roads in Canada where a 700km range wont get you to a gas station.
Yep. That new-fangled Trans-Canada Highway thing of yours has really changed the face of driving in the Great White North.

I remember when I was growing up in the 70's, I'd occasionally encounter an out-of-stater who would admit that he had thought that we still drove to work in covered wagons. :-)

-Steve

[sbergman27]

You are probably right BUT sometimes stations are closed or out of fuel.

Pay-at-the-pump has pretty well done away with "closed" gas stations. These days, I'm seeing more and more which are completely unattended. No associated convenience store or payment booth. Just a CCTV camera and some pumps with credit card slots.

Or at least I dont. 30 years of flying airplanes...
Yep. Sucks when the Astro-Shell runs out just when you really need it.

These roads arent normal though. They are the roads from Dawson to Inuvik and Fairbanks to Prudehoe Bay (Alaska I know)

You're going to want a good GPS that covers that area anyway. Go ahead and Amazon one in ahead of time to calm your nerves. Plot the route and select Destination->Point of Interest->Along route->Gas stations. I can set my TomTom unit to alert me when I am within x miles of a station.

BTW, while NAVTEQ maps are not my favorite, they do seem to have the most complete list of points of interest, including fuel stations.

I prefer my TomTom unit, but it seems not to know about many gas stations which do, in fact, exist. At least in OK, KS, CO, NM, and TX which is where I mostly drive.

P.S. And my! What a beautiful drive this will be!
Route on Google Maps (http://maps.google.com/maps?f=d&source=s_d&saddr=Inuvik,+Northwest+Territories,+Canada&daddr=Dawson,+ON+P0W,+Canada&hl=en&geocode=Fa69EgQd7U0J-CnRlvmVP5IUUTGEt683opEjUg%3BFbDd5wIde0xe-imrsJKAy7G-UjGUhYiXyqYkXg&mra=ls&sll=48.75,-94.483333&sspn=0.034634,0.110378&g=Dawson,+Rainy+River+District,+Ontario+P0W,+Canad a&ie=UTF8&t=p&z=3).

[MadMax]

:rolleyes:

[MUSKOKA800]

Or: what is the slowest speed you can go in a Yaris and still be in 4th? I ask because I may be driving in remote sections of Canada this summer where roads are bad and fuel infrequent. I will need to maximize fuel economy at times.

Thanks!

I honestly think that lugging your engine would yield worse mileage than driving with the rev's in the desired torque band where efficiency would be at it's max. Just be gentle on the pedal and let the Toyota engineering keep you in the pink.
Enjoy your trip!

[41magmag41]

I checked gas mileage yesterday morning with my scan gauge during the warm up run to work. It was 31 degrees out. With the transmission lock out until warm up at 40 mph in third gear the scan gauge read 32 mpg the entire time before the car reached 137 degrees and it kicked into fourth. I don't consider that lousy gas mileage.

I think all this yaking about overriding the computer to get better gas mileage for a couple of minutes will do more harm than good. I've just offered proof that the car still gets decent mileage when it's in the warm up mode before 4th gear is available. Why not leave well enough along. My girl has 98000 miles on her and I average 38 to 41 mpg year round when averaged together. I don't baby her in the interstate, run 75 to 80, and still get good economy.

Much to do about nothing other than to hear yourselves talk. Have a good day.

[bronsin]

I checked gas mileage yesterday morning with my scan gauge during the warm up run to work. It was 31 degrees out. With the transmission lock out until warm up at 40 mph in third gear the scan gauge read 32 mpg the entire time before the car reached 137 degrees and it kicked into fourth. I don't consider that lousy gas mileage.

I think all this yaking about overriding the computer to get better gas mileage for a couple of minutes will do more harm than good. I've just offered proof that the car still gets decent mileage when it's in the warm up mode before 4th gear is available. Why not leave well enough along. My girl has 98000 miles on her and I average 38 to 41 mpg year round when averaged together. I don't baby her in the interstate, run 75 to 80, and still get good economy.

Much to do about nothing other than to hear yourselves talk. Have a good day.


Yeah yeah yeah.

[41magmag41]

Yeah yeah yeah.

My point exactly about wanting to hear ones self yak. Proof given and even then we can't let the item go. :laugh:

[bronsin]

Now that you mention it... should be charging admission? :iono: