JDMToyotas

Is there anyone to get our second gen IS to changes gears faster? I would say this is only issue i have with the car. Lexus has built a damn good sport sedan the car is damn near perfect. Its the best car I have ever owned.

When you change gears there's that delay gets in the way someone of driving enthusiastically ... is there any programming or update to speed it up?

Jeff Lange

iTrader: (1)

The main issue is that there's no real way to change gears in the IS, all you can do it set the maximum gear the transmission is allowed to go to. So if you are at a light and it is set to 1, it won't shift above that, and if you set it to 2, it will now use either 1 or 2, depending on what it determines is the best gear to be in, since you are already at a high RPM it decides that 2nd gear is the best option. If you select 3, it will now use 1, 2 or 3; again, depending on what it thinks is best. If you slow down a bit, it will go back to 2 by itself even though you didn't select 2.

That's an important distinction between calling it "shifting" and calling it "gear limiting". There is no way to actually choose what gear you are in, just to restrict what the maximum gear the computer will select is.

There's no way to make it quicker that I am aware of, unfortunately.

Jeff

JD1324

Is this referring to when selecting from D to S and in my case it shows 4th gear and I have yet to see it upshift on to 5th on its own unless I select that gear

JDMToyotas

I was actually talking about when your using the paddle shift. Im fine with the other issue you brought up. When your on the move and changing gears there's a delay when in when you press the paddle and the car actually shifts

Jeff Lange

iTrader: (1)

Of course the car will not go to 5th, it is currently set to 4. It will however use any gears below that (1, 2, 3 or 4) at it's own choosing.

The transmission shifts in the same way whether you select the max gear using the shift lever or the paddle shift. The paddle shifters on the steering wheel are just connected to the +/- on the shift lever to the computer.

What this means is that when you have selected 2 and are driving and now press + to select 3, what are you are doing is basically unlocking 3rd gear and the computer can now use 1st, 2nd and 3rd gear, which if you're going fast enough, it will shift to 3rd, but you never actually told it to shift to 3rd gear, and that's the main reason for the delay.

If you aren't going fast enough, and you "shift" to 3, it will stay in 2nd. It's not a gear selector, it's a top gear limiter and you're never actually telling the car which gear you want it to be in when you use the paddle shifters.

In the end, there is no manual mode in your IS. In a car like the IS F, or the 3IS, if you select a gear, you're actually selecting a gear and it will shift much quicker and hold that gear. Even in models with the same transmission as the 2IS. If you can get a 3IS computer to work in your car, that would probably be the only way to get it to shift the way you want it to.

Jeff

redspencer

iTrader: (1)

What are your thoughts on the feasibility of swapping out certain Lexus/Toyota ECUs to alter the 2IS transmission logic from being a gear limiter to actually selecting gears? In the past, you've experimented with different IS-F Steering ECUs and found that they are perfectly compatible with the 2ISx50.

I don't know if the 6-speed auto has its own dedicated transmission ECU or not but if it does, perhaps swapping out the older ECU to an updated version might have a similar effect. Some of the potential candidates for the ECU swap could be the 3IS using the 6 speed auto, maybe the earlier model 4GS350 w/ 6 speed auto (I don't recall if the transmission behaved as a gear limiter or not), and possibly the Scion FR-S w/ the 6 speed auto (it uses a similar Aisin 6 speed transmission that also allows you to select gears).

is25019

really? my 2is lets me shift up to 4 after that 5 and 6 is done by car, but 1-4 i have to shift it in sport mode or it dosnet shift

Jeff Lange

iTrader: (1)

The engine and transmission control is all done by a single computer, so the only way would be to see if a 3IS ECU with the same transmission can be used, but I wouldn't necessarily count on it, they made quite a few changes electronically between the 2IS and 3IS.

Jeff