Sending ECU for rebuild due to known hard downshift issue. Have seen conflicting info regarding ECU location for removal in my 2006 LS430. Can anyone confirm ECU location for my model? Thanks!

 

There are over 40 ECU's on the LS430. Attached are the pages, from the factory repair manual, showing the locations of various ECU's. For transmission shift, I suspect you're looking for the ECM (Engine Control Module). The ECM is located in the engine bay.

 

It's right behind the driver side headlight. There are 3 10mm bolts to take the cover off and just unplug and ship it out. I had to deal with this in June, sent it to SIA Electronics and they had it back to me in under a week.

 

How much were you quoted for the ECM flash to fix the shift calilbration?

 

I was invoiced under $150 for redoing the transmission circuitry, which was surprising bc it's listed at a higher rate on their website.

 

Wait... "redoing the circuitry'?? Is this supposed to be the same fix that dealerships do when they flash the ECU to update the shift logic? (which is a TSB from Lexus describing "poor shift quality at low speeds" including rough downshifts, jerky acceleration, and transmission 'gear hunting' at lower speeds under light acceleration) If so, the dealers don't actually change circuitry... they just plug into the car and "flash" the ECM, which technically is more than strictly installing software (google what flashing/reflashing a computer chip means). I paid my dealership $180 to have them do this for me and only took them about an hour or two... didn't have to take my ECM out and mail it anywhere, rendering my car un-driveable until I got it back in the mail. Can you post a link to the website you're talking about? I'd like to read what exactly they plan on doing to your ECM and what that's supposed to do for you.

After getting my car back from the dealer after the flashed the ECM, it fixed all those problems for me and drove like a different car (in a good way).

 

It is not the reflash, that TSB was onlyfor 04 models and early 05. Mine was from March 2005, so the reflash would not have done anything. I took it to the dealership and the were sure I needed to have my transmission rebuilt, they said there is no way it is the computer.

I was experiencing a harsh downshift from 3-2 then a violent downshift from 2-1.

This thread has some info on it, most recently post #36 to the end: https://www.clublexus.com/forums/ls-...1st-2nd-3.html

Also on here someone chimed in with their experience, 3rd post down: https://repairpal.com/poor-shift-qua...low-speeds-550

Here is the website for SIA http://siaelec.com/

It fixed my problem, I was shocked when I popped the ECM back in and everything was smooth as butter.

 

I was under the impression that it was an update that was either available on all '04-'06 models, or at least applied to '05 models manufactured until something like April-June of 2005. I briefly searched for the dates/affected VINs but couldn't immediately find it. If you've asked the dealership if that update is available for your car and they said no, or if you're otherwise sure that this update isn't available on your car, I believe you.

 

Hope the attached PDF has the information you're looking for...

 

Ok, gotcha. So obviously you've checked and your VIN is after the number listed...

Thanks for the clarification.

 

unagijimbo: Thanks. It is in transit to SIA Electronics.

 

My 04 LS430 UL has gotten this virus where I initially had the check eng light with a vcs on and a hard shift from 3rd to 2nd and really hard from 2nd to 1st. Indie found up lock up solenoid stuck and replaced. Ran fine for a day and its back to hard shifting and with no lights.

So I've sent the ecu off to SIA and waiting for the return.
However I was curious about this "Technical Service Bulletin dated Dec 6, 2004" and is this possibly what SIA might be doing or at least incorporating?

 

Got my ECU back today and it happens to be the rainiest day in months. But I do persist and went for a short drive and "EUREKA". Shifts as smooth as butter.

Thanks to all those who pointed in this direction. SIA rules. Get the deal on ebay, its only $135 as opposed to on their on web site, its listed as a $180 job.

Praise be...

 

Hagar, wher eon ebay..what do I search for?

 

Sorry your having some problems finding it. I simply went on Ebay and typed in SIA ECU repair, and its even cheaper then before. $115.

https://tinyurl.com/6rxhhjr

Good luck, Car still runs better then when I bought it somehow.