Mod- built a shift-controller for Gen3 auto transmission S-mode using microcontroller

OP, @dcz108

Please hack the ECU and build a 93 octane tune so we can have 311 HP like the Lexus GS-350

Sincerely,
Everyone

 

This seems great. However, if something does happen to your vehicle, a tech can see if something has been plugged into the system or, "changed". This might throw that red flag. Just saying.

Better question. Why do we need learning transmissions? What ever happen to a transmission simply shifting during a load or RPM range? Seems silly to have a transmission learn my driving habits. I feel for the people that have a wife or significant other drive the vehicle also.. Mass confusion!

 

Or learning from a negative situation like a 15 mph headwind (or even crosswind) and my truck is stuck in 5th gear because it isn't strong enough to maintain 6th gear on a flat road.

 

Pretty sure you aren't going anywhere fast if you push the left pedal further.

 

It's not that it's not strong enough, it's that it gets better mpg.

My experience and my calculations using the "ABC" coastdown coefficients Toyota provides to the EPA and the 2GRs BSFC map indicates that at any speed it will almost always improve mpg to downshift to 5th when going up an incline.

For my theoretical level road / no headwind calculation at 80 mph, the truck gets about the same mileage in 5th or 6th. Above 80, 5th is better mpg. The headwind calc adds an additional term that I haven't calculated yet; but, a 15 mph hw would obviously move that number down around 65 mph. (Those numbers are approximate as I need to experimentally verify one term that I am currently guessing at. Also, I am using OR DC 4WD specs.)

One other interesting note: according to the ABC coefficients (i.e. drag=A+Bv+Cv²), the reason full size trucks get almost the same hwy mileage as a Tacoma is because they have almost the same hwy drag. (Higher A and B; but, lower C.) I suspect this is mostly due to the super low hanging air dams other manufacturers use.

 

Next stage of this modification... see if its possible to issue the up and down commands over the CAN bus. Then the physical aspect of this modification turns into a bluetooth ELM327 and an Android phone (or head unit!).

@OP: If you were considering distributing this modification, there are LOTS of aftermarket car performance companies that sell MUCH crazier things. You might be able to find one to distribute the device *and* assume liability (since they're already taking on liability for all the other stuff they sell).

 

Except if you did that, I don't think you are relinquishing control to the truck, which needs to exist as a safety feature.

 

That is incorrect. Issuing the command over CAN would be no different than pressing the button. It is still up to the receiver of the command to honor the command or not. CAN bus is a protocol for transferring commands between different components within the network, and without a centralized coordinator.

Think about it like this;
You have a bunch of devices on your home network. One of them is a device that controls the lights at the front door. It has a "safety" feature where it checks the input from an ambient light sensor to make sure it is dark out for the light to turn on.

Another device on the network is a SWITCH. It is a REALLY STUPID device that only sends commands (ON or OFF) to the LIGHT. No error checking, just sends the commands. The LIGHT is still going to handle error checking.

Now you introduce a THIRD device to the network. Your CELL PHONE. You've rigged it to send the same commands as SWITCH does, to LIGHT.

Now, you can send the command by interacting with SWITCH, or you can send the EXACT SAME command by interacting with CELL PHONE. The "safety" (error checking) is *STILL* handled by LIGHT. Security has not been compromised.

 

i was actually thinking this would be similar to something hypertech sells for the diesel crowd. i was thinking, they do tuning/remaping for the diesel enginers, this is a very similar application. hopefully someone does it to that level. when i had my TDi you could go to any number of shops, have them flash in a new tune and have all kinds of better hp/torque/shift points

 

That's not a choice you can switch between. You can't just put a manual trans in on the fly on an automatic transmission equipped vehicle, and S mode obviously has it's fallacies that is to now be expected of 3rd gen auto equipped vehicles at the higher gears. Not exactly a choice between eco mode and sport mode at highway cruising speeds if it still shifts like trash.

 

He means a choice when you're ordering it.
Like you choose between the 4 and 6 cyl engines, or between access and double cab. Prerunner and 4x4.

 

Great job !!!
Using S mode only ....eliminates pulse width modulation
There is a programmer on the market for a similar transmission ...The AB60 .
http://www.ukrtrans.biz/files/2011/10/Toyota_AB60_Transmission.pdf
I will dig it up and ( edit ) post it here when I find the link . If memory serves me correctly , the programmer is already in high circulation on the other side of the pond . The AB60 series transmission is widely used in heavy delivery vehicles in Europe and aftermarket shops are offering the controller to alleviate some of the same complaints you guys have with your 16 trucks .
There is talk of making the controller available for the AC60 series transmissions found in the new 2016 / 2017 Tacoma

 

How is buying an Automatic or Manual trans not a choice? One of the reasons some folks stay with the Taco, is the fact it's almost the only manual trans vehicle you can get now.

 

I don't understand why manuals are even a discussion in an automatic transmission thread.

The only choice the guys who are in this thread made was to buy an auto. Due that to various reasons where either A. The trans was not available how they wanted it or B. They have some sort of personal injury that doesn't allow them to use manual. Which means that us automatic owners are stuck with whatever poor performance the slush boxes are capable of or lack thereof. That means for the Tacoma there are a lack of options on it's shifting performance parameters from the factory.

 

I brought up the manual as some one stated yota didn't offer choices. And again if your looking for shifting options the manual is certainly an option. If some one wanted that and it wasn't available, then they should have done what a lot of others, including myself, demand the mt. I am not here to take away from the fantastic work of the OP.

 

Awesome work!

I just find it so sad that it's 2017 and we are adding parts to this truck to make it shift correctly and have a liveable driving experience. I'm so tired of the "it's a truck...you should of bought a sports car" apologists. The trucks transmission is terrible and the motor is so underpowered.

 

I think the transmission is perfectly fine. I found that out on my test drive.

 

I feel that there should be more of an offering of the MT myself, as there should be choice for it given it is marketed as an offroad vehicle. I get it about CAFE, bla bla bla bla, but if that is the excuse they better offer a different workaround to gain better driveability at the expense of gaining exceptional fuel economy for a V6 truck.

Again though, some of us have injuries which won't allow us to endure the ability to use MT forever, so we opted for the AT instead. The lack of selection they offer for shifting patterns and configurations on the auto is what is angering.

Maybe the issue is not them limiting the amount of MT configurations over auto. Maybe quite possibly, It is the restrictions placed over them federally which forces them to produce a certain amount of them which are able to acheive better mileage. Manual trans equipped cars are no longer kings of the hill when it comes to saving gas like they once were. Or so we have been told.