2015 vs 2017 transmission behavior

[mashburned]

I don’t really know enough transmissions to properly express what I’m trying to say here, but I think you guys will understand, and hopefully smart guys can help me out:

Just got done driving a 2015 on a long trip, and now my 17 feels like a total b****. My 17 will jump to 5th gear as fast as it can if you apply any pedal pressure. You have to slam the gas to get any real power. Driving around town is annoying as hell, and I pretty much stick to s4. You get used to it, and it’s “fine”...till you drive the same vehicle with different shifting points.

The 15 shifts and drives like a normal vehicle. It feels like an absolute sports car compared my 17. It’s not in a race to 5th gear. It gives you power when you push the pedal. It’s not constantly switching gears. It just drives like a normal “truck”. A 275 horsepower vehicle. It sounds good, and has ample power. Great highway cruiser.

The 17 feels totally different because it’s constantly fighting you to stay as close to 1k rpm as possible.

Anyway, how do I get my 17 to behave/shift the same way the 15 does? Can Toyota give me 2015 software? It seems like there would be a simple resolution to this.

 

[Jetboy]

The transmission learns how you drive. I would be surprised if there were actually a different software in the ECU. Probably just a different learned driving style.

 

[thennen]

Since all manufacturers have to achieve increasingly better and better fuel efficiency across their lineups, I wonder if Toyota has tweaked the shift points to get an extra mpg or two out of the Runner. I don’t notice anything unusual with my 2019, but I drive with a light foot and also have nothing to compare it with.

 

[mashburned]

The transmission learns how you drive. I would be surprised if there were actually a different software in the ECU. Probably just a different learned driving style.

Cool, so can I reset it, and “relearn” it?

Since all manufacturers have to achieve increasingly better and better fuel efficiency across their lineups, I wonder if Toyota has tweaked the shift points to get an extra mpg or two out of the Runner. I don’t notice anything unusual with my 2019, but I drive with a light foot and also have nothing to compare it with.

That’s kind of my thinking. When I bought mine in ‘16, a popular and unsubstantiated rumor was that the T4R could be going away, or at least could be redesigned to meat increasing EPA standards...perhaps like what they did with the new 3.5 Tacoma’s.

It’s not a big deal, and you wouldn’t really notice how big the difference is unless you drove a 4Runner with a different “learned” behavior. It was very significant in my experience.

 

[Jetboy]

I don't know the procedure, but yes you should be able to reset it and it will relearn how you tend to drive. It's called AI-SHIFT control and uses input from a variety of sources and your driving history to guess at how you want it to shift. I don't know a whole lot more than that. This is the quote from the service manual from the transmission:

AI (Artificial Intelligence)
-SHIFT Control
(See Page CH-32)
"Based on the signals from various sensors, the ECM determines the road
conditions and the intention of the driver. Thus, an appropriate shift pattern is
automatically determined, thus improving drivability."

 

[BobsTrail]

I run my 2013 in S5 all the time. It helps the shift points a little and helps the freeway ramp downshift a lot.

Disconnect the battery for a while, I think that will cause the relearn to happen. Then drive it like you normally would.

 

[mashburned]

Ok, thanks for info. I’ll try disconnecting, then driving it like I stole it. Learn fast and responsive, Toyota!

I’ve seen some threads about the pedal commander thing, and I think the “issue” I’m describing is what people are trying to remedy with the pedal commander. Maybe not.

I just want my 4R told hold gears longer and use more power, but sounds like I need to teach the AI that by driving it harder and letting it know I don’t care about gas mileage.

I’ll try s5, too. I just assumed s5 was exactly the same as D, but if it holds gears a bit longer that would definitely help.

 

[Lester Lugnut]

When you disconnect the batteries negative cable and later reconnect, the vehicle will likely stumble the first time you start it. Nothing to be alarmed about. Mine does this, both '15 Tacoma and '14 4R. Both use the A750E 2WD transmission, at least mine do. 4WDs use the A750F transmission. I do not know the year range for the A750F transmission.

People have complained about the stumbling occurring repeatedly over a number of days. Some believe this is because the throttle body plate is dirty and now that the transmission is in a learn mode, the TB plate may need cleaning. I picked this up from a knowledgeable tech at tacomaworld.com

 

[wcjeep]

We have a 2017 and 2018. They drive differently. Wife drives the 2017. It's more aggressive with transmission shifting vs my 2018.

 

[mo_mo]

I don't know the procedure, but yes you should be able to reset it and it will relearn how you tend to drive. It's called AI-SHIFT control and uses input from a variety of sources and your driving history to guess at how you want it to shift. I don't know a whole lot more than that. This is the quote from the service manual from the transmission:

AI (Artificial Intelligence)
-SHIFT Control
(See Page CH-32)
"Based on the signals from various sensors, the ECM determines the road
conditions and the intention of the driver. Thus, an appropriate shift pattern is
automatically determined, thus improving drivability."

I wonder if this plays into cruise control and when/how it will shift relative to a given terrain.

 

[Jetboy]

To fully reset the ECU learning you need techstream and you'll need to go into the file and select a full delete of learned parameters. The battery disconnect is essentially a short term memory loss. It will not fully reset the full set of ECU learning files. The battery reset method is probably worth trying first before going through the full process.

 

[mashburned]

To fully reset the ECU learning you need techstream and you'll need to go into the file and select a full delete of learned parameters. The battery disconnect is essentially a short term memory loss. It will not fully reset the full set of ECU learning files. The battery reset method is probably worth trying first before going through the full process.

Ok, thanks for the info. I need to look into that. I could have very well made my 4runner dumb and unresponsive.

Drove around in s5 this morning. That DOES make a difference. It was quicker to downshift while going up hills. I didn't have to stomp on it to let the dumb AI know it was going up a hill. Little to no hunting for gears when I'm cruising, it just behaved "normal".

I love this forum. Only problem is it gives me questions that I want to take to my dealer and get some answers to, but they never have answers. I need to find a reputable/helpful dealer or independent toyota guy that's willing to help a guy out.