Re-Gearing, Tunes, and the 3rd Gen Dilemma

Let's see if I can make a coherent post without the riot section pelting me with tomatoes.

I read though the OVTune and re-gearing threads a lot among other sources. My 2020 does fine on the highway, no "gear searching" but does have its sluggish moments coming off stoplights or in traffic between 1,2,3 gears. This isn't a problem because Toyota installed ECT Pwr and S-Mode. Most of the time in city driving I either use ECT Pwr or just put S-Mode in 3rd and leave it there. Problem solved -- shift points remapped. All the torque I need. I especially like S-Mode in 3rd in city traffic.

But still there is no reason for regular "D" to be sluggish in those lower gears. The transmission is a moose as is the V6. Nothing wrong with them.

It's all software and in particular the parameters to which that software is set in the ECM.

For 25 years I have fed and clothed myself and family as a software engineer in the scientific applications field with degrees in computer science and mathematics.

I highly commend the people at OVTune. They are brilliant. I have read through their "white papers" on their website and learned a lot about the ECM with the 3rd Gen Tacomas and transmission.

A 3rd Gen Tacoma's transmission shifts non-sequential. It can shift from 1st to 3rd or 4th to 2nd and so forth. That is different than previous generations which shift sequential, i.e., 1st to 2nd, 2nd to 3rd, and so forth.

The 3rd Gen's ECM is always looking for the lowest RPM when making a shift decision. So when starting out from a stop light the truck may go from 1st to 3rd and skip 2nd all together.

The danger in reverse engineering the ECM and reprogramming it is that without the actual source code these changes are just a guess as to what it truly affects throughout the software system.

Software systems need regression testing when changes are made. If a "minor" change is made to peddle response, has the DRCC (driver radar cruise control) software module been regression tested? If not it can be a real danger when "tested" in an actual driving exerience when DRCC braking is needed.

As for re-gearing? I don't see the point when the issue is 100% software related. And my understanding is that the ECM re-learns the new gearing and starts non-sequential shifting for the lowest RPM. That is what the ECM was written (trained) to do.

So here is the reason for me writing this post:

The Tacoma World forum is a VERY powerful voice that if channeled can get the people in corporate Toyota to respond.

Since the Toyota engineers have the ECM source code, can see the complete source code, and can do regression testing on the source code... And do it safely.

Why not petition Toyota corporate for flash updates to the ECM with the 'Tacoma World' community giving them specific well defined performance parameters?

It's just a software issue and they are making people jump through hoops when those corporate monkeys should be jumping through hoops for you, the people who just purchased 260,000 Tacomas each year.

 

Too bad there is no tomato emojis

No but good post, but i cant add anything since i dont know much about 3rd gen ATs and the ECU programming.

 

Lol on Toyota jumping through hoops for 500 people at Tacomaworld. Trust OV Tunes. They worked with Toyota so Toyota could make their changes in their software.
Enjoy your truck or not. It's up to you.

 

Wait, OV tune worked with Toyota engineers?

 

Lol I wish

The factory tune is hot garbage and it’s taken them years for Toyota to release minor updates to these trucks after many many complaints.

The auto is geared way too high from the factory, why they did it is a mystery.

this truck is capable of so much more as OVT has proven. Zero regrets tuning my truck

 

https://www.tacomaworld.com/threads/2016-toyota-tacoma-ovtune-1-05-tune-development-thread.495735/page-903#post-18033842

https://www.tacomaworld.com/threads...lopment-thread.495735/page-1877#post-19892396

 

I concur, but my sense is that Toyota engineers have a lot of fires to put out and that the Tacoma ECU checks most of the boxes they needed to check. The gap between how the truck performs and how it CAN perform provides entrepreneurial opportunities for the folks at OVTune and code-inclined folks like yourself. Its the American way.

 

Yes.

 

Emissions. EPA certification, CARB certification, whatever governs emissions in Canada, etc. Mess with the software and you have to mess with emissions. I’m not sure what hoops Toyota has to jump through for get TSB updates approved, or if there is an approval process. Remember the VW diesel emissions scandal?

 

Hey OP, this made my day! Thanks!

"Let's see if I can make a coherent post without the riot section pelting me with tomatoes."

 

I'm not trying to call you out on this, but disassembling the code that is read directly from the ECM is essentially "source code". While it may not be in the pretty readable format of a higher level language, it is the actual code. Mat (OVtune), has posted many times of the reverse engineering he was (is) doing at the assembly level. I think he was using IDA. Toyota will never release their calibrations in any editable format. We are lucky we have a way to get the TSB CUW files so we can update our *STOCK* trucks when the dealer won't.

As far as testing, Mat bought a truck for this sole purpose and did extensive dyno testing. Prior to that the early adopters tested files on our own trucks.

While I agree with you in principle, what you are asking for will probably never happen.

 

Bump.
I appreciate this post and I’ll petition Toyota with you.
Not sure why a 3rd party company which, in reality is a small business, should have to fix a problem that a major, giant corporation should be tending to.

 

As I already said, I agree in principle, but I don't think this is the right way to approach it.

I think the better target is supporting right to repair laws that are applicable across the board.

 

This. Plus the fact the tacoma has somewhere near 49% market share. Why change? Stop buying them. Get something like say a Colorado maybe. The only way to force change is to prove liability or affect market share. Your purchase power is undeniable. A petition is toilet paper with writing on it.

 

Lol @ some people still claiming that "a few TW whiners" doesn't mean there are issues with the 3rd Gen V6 ECM programming.
No shit Sherlock.
You know what does get Toyota's attention? Probably a large number of complaints about the same thing.
How many? Don't know.
Neither do the gaslighting crowd that invariably defend the 3rd Gen with nothing but sales numbers as absolute proof that nothing is amiss.
Well then, how come Toyota changed their calibrations several times to address.. you guessed it.. driveability issues directly related to the complaints you see on this forum?
Oh I know, it was just to appease the 500 or so whiners.
Yeah, totally see Toyota doing that.

 

Yep this actually happened.

Mat isn't just some backyard hack with a laptop playing with table entries as some would believe (not referring to you).
He reverse engineered the code and made changes at that level.

 

Hey,
at least us 2016, 2017 owner's wont lose sleep about cruise control radar software regression being an issue... AMIRITE?

 

I’ve got nothing of value to add...except for...Regression testing...There once was a smart computer scientist named Edsger Dijkstra. He even taught in Texas at UT Austin before he passed. He was a big formal methods guy, you know, proofs of correctness, etc. Always the idealist and never the realist he once made a profound statement. “Testing can only show the presence of bugs, never the absence.” Being a math guy that shouldn’t surprise you. You know proving the non existence of something when you cannot use neither induction nor enumeration of all possibilities.

In all seriousness, good post.