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Could the people with the ECU flashing give an update? I did not choose to go that route, but found the solenoid causing these rough shifts and my car continues to run and drive perfectly ever since I replaced them. I'm curious as to how the other proposed solutions panned out.
Could the people with the ECU flashing give an update? I did not choose to go that route, but found the solenoid causing these rough shifts and my car continues to run and drive perfectly ever since I replaced them. I'm curious as to how the other proposed solutions panned out.
SIA performs hardware fix (resoldering plus testing), while flashing ECM is offered separately. Which year is your Lexus? If it’s pre 2005, it may need software fix first, but you need to check by VIN.
So far, the SIA fix resolved all my concerns. I rarely feel the transmission engagement, and if I set my controller to Eco Mode, it slows down shifting speed which I found amazing for travelling and relaxing cruising. ECM is definitely coordinating with solenoids and other systems in the way it is supposed to.
Now, if the solenoid is malfunctioning or friction plates are worn, ECM won’t resolve transmission problems.
My LS430 had the dealer software update specified in the TSB by the previous owner. All of a sudden it started the shifting problem at 137,000 miles.
I had the ECM inspected at a nearby ECM repair facility. They did some testing (what or how I do not know) and visually inspected the board for bad components and traces and found none. Can SIA find something the other shop didn’t? I seems to be a flip of the coin as to the cause and how to proceed.
SIA charges $125 on ebay - not a bad place to start imo.
Originally Posted by mdpresco
My LS430 had the dealer software update specified in the TSB by the previous owner. All of a sudden it started the shifting problem at 137,000 miles.
I had the ECM inspected at a nearby ECM repair facility. They did some testing (what or how I do not know) and visually inspected the board for bad components and traces and found none. Can SIA find something the other shop didn’t? I seems to be a flip of the coin as to the cause and how to proceed.
SIA charges $125 on ebay - not a bad place to start imo.
If SIA finds the ECM good then $89 for diagnostic fee.
As soon as I get my LS 430 back from its timing belt job I'm going to perform the ECU reset. If this doesn't help the hard shifting at 55 mph then I will send the ECU to SIA.
To reset the ECU without losing your seat and stereo settings, perform the following procedure:
1. Get in your car and insert key. (It doesn't matter if you close the door or not.)
2. Turn the key to the on (not start) position.
3. Press the gas pedal to the floor.
4. Hold the pedal to the floor for five seconds, then turn the key back to the "off" position (don't remove the key), then release the gas pedal.
If SIA finds the ECM good then $89 for diagnostic fee.
As soon as I get my LS 430 back from its timing belt job I'm going to perform the ECU reset. If this doesn't help the hard shifting at 55 mph then I will send the ECU to SIA.
To reset the ECU without losing your seat and stereo settings, perform the following procedure:
1. Get in your car and insert key. (It doesn't matter if you close the door or not.)
2. Turn the key to the on (not start) position.
3. Press the gas pedal to the floor.
4. Hold the pedal to the floor for five seconds, then turn the key back to the "off" position (don't remove the key), then release the gas pedal.
Several people have said that it solved (at least temporarily) the rough downshift issue. But I just experienced the rough downshift issue tonight for the first time, tried this procedure three times and it did nothing.
I am not a happy camper because I just bought my 2006 LS430 with 64k miles from a Lexus dealer less than a month ago. All was well until this evening, the day that I drove 5 hours to Los Angeles for a weeklong getaway. I have to drive a lot while I'm here and just going to the grocery store and back tonight was unbearable with this problem.
If I was at home I would try the SIA rebuild route but I don't have that luxury since I need my car while I'm on this trip for the next week. Is the fastest solution a new ECU? I really don't want to do that but I cannot live with this problem. And here I was switching from older BMWs to an LS430 thinking I'd be avoiding reliability issues! =(
Can anyone chime in? Thank you in advance, I'm just really caught off guard by this problem, especially when I'm on vacation.
Just get into the habit of shifting to neutral at 20mph when coming to a stop. If you forget, the car will remind you.
Take it to the dealer to retrieve any codes. The ECM repair route is the quickest to try and very easy to do. If that doesn’t work, plan on spending some time under the car testing solenoids.
Good luck and enjoy the remainder of your vacation.
Update - Received the ECU back from SIA, and drove car around today a bit. Hard shifting is completely gone, and car drives perfect, just like it did before.
Going to take it out tomorrow for a small road trip, will post again with update. (Cross posting from another thread)
Update - Received the ECU back from SIA, and drove car around today a bit. Hard shifting is completely gone, and car drives perfect, just like it did before.
Going to take it out tomorrow for a small road trip, will post again with update. (Cross posting from another thread)
Congrats! Would you be so kind to share what SIA wrote in your ECM’s diagnostic list?
Now that you fixed hard shifting, consider if the eco smart controller could be a great addition as well. It lets you switch between throttle and economy mode in real time, and it does work well with fixed ECM - shifts smoothly and lets you set the tone of car acceleration - from instant response to slow rpm increase to improve fuel economy.
Thanks! And I appreciate the info - I always want instant response! and only drive about 2000 miles per year, so MPG is not really a concern. Here is photo of receipt they included.
Originally Posted by ls430w140
Congrats! Would you be so kind to share what SIA wrote in your ECM’s diagnostic list?
Now that you fixed hard shifting, consider if the eco smart controller could be a great addition as well. It lets you switch between throttle and economy mode in real time, and it does work well with fixed ECM - shifts smoothly and lets you set the tone of car acceleration - from instant response to slow rpm increase to improve fuel economy.
Just wanted to provide an update to my situation above while I was on vacation in Los Angeles. I took it to a top-rated transmission shop who immediately knew it was the ECM. They had it rebuilt and two days later I got my car back. Good as new. Not the way I wanted to start ownership of my car but the important thing is that it's now fixed.
SIA performs hardware fix (resoldering plus testing), while flashing ECM is offered separately. Which year is your Lexus? If it’s pre 2005, it may need software fix first, but you need to check by VIN.
So far, the SIA fix resolved all my concerns. I rarely feel the transmission engagement, and if I set my controller to Eco Mode, it slows down shifting speed which I found amazing for travelling and relaxing cruising. ECM is definitely coordinating with solenoids and other systems in the way it is supposed to.
Now, if the solenoid is malfunctioning or friction plates are worn, ECM won’t resolve transmission problems.
I just got a lexus ls 430 2004 117000 miles. Did a drain and refill from the lexus dealer...Occasionally i notice RPM shoots to 2000 during left or right turn but no hard shifts but it just lacks power during stop and go .I was thinking of sending the ECU to sia electronics but was confused whether is it worth the risk.
Please advice if i am wrong..
1) Detach the negative battery cable
2) Detach the ECU
3) Re attach after rebuilt from SIA
Now are their any other process that needs to be done .. What happens when they sent a replacement unit will that need re programming ...Thanks for any advice...
@ls430w140 and @Peacebay , thank you both for your ongoing communication here. I want to get clarity one more time. I have an 04, post-recall, and I am having the 2-1 downshift thing at times. My 03 LS did it too, but it seems to be more pronounced. I did the 5-step accelerator pedal reset thing and it was great, but like Peacebay said, it re-learns like Terminator 2. Are you thinking that a flash at the dealer can fix this, or I need to send out my ECU to SIA or equivalent? This is my only car, so sending to SIA means a week and half in a rental.
@robbyboy32 , I am not a DIY-er. When you say transmission solenoid, I am thinking $$$. Am I right? Seems like chip fix is the better route?
@Kodawari , thank you for your story. Based on your results, would you say I could find a place in the Seattle area that knows what to do, and hence not have to send out to SIA?
10-10-20, 04:45 PM
