notajerry

Hello all. I have a few questions that I am trying to figure out.

Last thursday the car would not shift up (when in standard drive) once you stopped the car and put it in park it would go back to normal. It did not do it all the time or every time. I noticed that it shifted a little rough also just driving normal. the other thing it did was down shift like crazy! when I got off the interstate and applied the brake it went all the way down to 2nd while I was still around 45mph. When It did that I switched to the paddle shifting. When using the paddle shift I had no issues. This makes me believe that it is an ECU problem. So my question is Can I buy a ECU and put it in the car to see? Or will I have to have the ECU programmed for my car? I would also like to here your guys take on this? Car is a 2006 IS250 has 137,000 miles. I

Thank you in advance.

getafewliv

First thing I would try is resetting your car's ECU. Easiest way is to disconnect the battery for 10 minutes. There's a better way to do it, but you'll have to search for it. If you do the battery method, you will have to re-calibrate the windows and memory seats to get them to function properly again.

If the problem persists, I would look at getting your transmission fluid changed.

notajerry

^Thank you.

MWIS350

Bring it to dealer they can scan the code and recalibrate your transmission ECU for about $70.

notajerry

Reset the ecu.... SO FAR SO GOOD! Drove it for 20 miles yesterday and no problems. What is the chances that the transmission is going out? I know it has lifetime fluid in it and have read several times you can not change the fluid.

getafewliv

Personally, if it is driving fine, I would just leave it and keep an eye on how it behaves.

The fluid can be changed, and nothing lasts forever. There's mixed opinions on when and if to change the transmission fluid. I am pretty sure someone here did a test on their fluid when they changed it at like 100,000 miles (don't quote me) and the fluid tested fine.

Zynthe

iTrader: (5)

Isnt the transmission a closed system? Ive also read mixed messages on changing the trans fluid.

I was going to change it as well (I own an MT) but was advised since its a closed system theres no need to change it (life time).

notajerry

OK. So it did not fix the problem. I drove normal for about 20 miles. It down shifts hard as hell. Upshifting is no problem. It was good until I got it above 55 Mph. So next step is I want to change the ECU to see if it fixes the problem. I know on honda's you can swap and ECU no problem, Is it the same for a lexus? I can get an ECU for about 140.00 I can not even get it looked at by a dealer for that.

MWIS350

Bring it to dealer they can scan the code and recalibrate your transmission ECU for about $70.

Gville350

iTrader: (10)

Was it you that had your trans ecu reflashed by the Lexus dealership?