You can set the max gear, which will downshift if it's currently in a higher gear, but the car can still choose to be in a lower gear than what you set, and you can never tell it to upshift, unless it would normally be in a gear higher than you've set to max and you up the max gear.

So yes, you can kind of downshift to any gear, but it is not like in a car that has a proper manual gear selection (like the IS F, or a car with a manual transmission). The ability to hold a gear just isn't there, nor is the ability to make an exact, specific gear choice and have it just DO it. It's still in an automatic mode and it still will change gears without your input.

Jeff

 

Yeah, the paddles don't let you downshift. Ever. They are not shifters.

They only let you lock out higher gears from the fully automatic transmissions use.


So if you're are in S-6 the fully auto transmission is a 6 speed auto.

If you paddle to S-4 it's now a fully automatic 4 speed.

You never, ever, can directly command a shift... the best you can do is tell the fully automatic transmission it's not allowed to use a higher range of gears anymore, which can, sometimes, cause it to, automatically, shift to a lower gear, if the one it's in now is in the range no longer allowed.


Go drive an IS-F in M mode if you wanna see the (very substantial) difference.

 

My favorite update about my 09

 

He's right. I love this mode on the loaner cars but its only on 09+

Switching to S mode always puts you in 4th. But if you're driving in D and the car is only in lets say third (09+) and you hit the down paddle it will drop you into 2nd for quick acceleration then if you let off the gas or stop accelerating the number on the dash will disappear and the car will drive like normal.

I would think its a simple ECU upgrade but I've asked my dealer and they didn't seem to care to bother coming back with a solid answer.

 

What about swapping transmission ECUs from the 2009+. Would that retrofit the feature he's after?

 

There is no separate transmission ECU, it's integrated with the engine ECU. Some other features changed along the way, so I'm not 100% sure how easy it would be to use a newer engine ECU on an older car.

:\

Jeff

 

There has to be a way to override the crappy tiptronic...

 

Get the ISF shift any where u want manual or auto lolz . In automatic mode u can use paddle shift too

 

Jeff, please review the following links...
http://www.lexuspartsnow.com/parts/l...535-50013.html

http://www.lexuspartsnow.com/parts/l...535-53010.html

These are for the ISF and the LS460, but I'm almost certain the IS250 has it's own transmission ECU.

 

My '10 IS250 can downshift-upshift anytime I want it, be it in D or S mode. Only when my car is coming to stop is when the paddle shifter stop working. When the car is running I have full control of the transmission (in a logical sense, that is).

However, It just won't do silly thing illogically. For example, when you are running at 80 mph, it won't let you downshift to second or first gear. Or it won't let you upshift to 6th gear when you are crawling at 20 mph. No one will drive like that.

 

I apologize if this was covered but without searching why not just swap an 09+ Tranny ECU into your 06? I assume the 09+ still has a tranny ecu vs built in with the engine ecu?

 

You can not upshift or downshift your car manually... ever. You have an automatic transmisison. Always.

The only thing the paddles can ever do, on any year ISx50, is set the maximum gear the transmission is allowed to use. That's it.

This sometimes fools you into thinking you are directly shifting the car, but you never, ever, are.

really.



If you're doing 60 and you "paddle" down to 3, you're telling the FULLY AUTOMATIC transmission it's no longer allowed to use any gear higher than 3, so it will be forced to downshift to 3. You didn't "shift it into 3rd" you simply locked out all gears above 3rd from the automatic. It will remain a fully automatic transmission using gears 1, 2, and 3 as it sees fit.

Change 3 for any other # and behavior remains the same. A fully automatic transmission where the paddles never, ever, do anything except limit the max gear the automatic transmission is allowed to use.

 

This worked for me. Not only that, but when you lift off the gas, it throws you against the belts just like a manual because the torque converter is locked. Can't beat it for function even if the AA80E gearbox is less than stellar.

 

The IS250/IS350 are not so equipped.

Jeff

 

yea probably need a stand alone unit like SupraStick. Wish they did it like MB, their autos seem to hold gears just fine.