@93ls400walt....Thanks
Your good suggestions have already been tried.
Regarding a rebuilt ECM, I learned a lot when I had mine "rebuilt". Generally, "rebuilt" only means that the electrolytic capacitors are replaced, and any damage caused by leaks is repaired. I was informed that the capacitors can/do leak and cause problems. I checked my ECM capacitors thoroughly before sending in the ECM. All capacitors and other components looked good. The salesman guaranteed me that if their “rebuild” didn’t solve the malfunction, (he was confident it would) he would refund the rebuild cost. Well, it didn’t, and the salesman left the company right after shipping me the “rebuilt” ECM. The company wouldn’t refund my money without me sending the ECM back to them for further testing. I did. They claimed it worked fine, which, as it now appears, was working fine when they first got it. I finally got my money back after a fight with the company, but the multiple shipping costs was almost the cost of the “rebuild.”
After much more testing, I thought that maybe the programming in the ECM was at fault, so I got another ECM. As mentioned in my original post, the second ECM didn’t solve the problem.
The moral of the story is this: if one has good electronic experience, then they can open the ECM, check for faulty (leaking, swollen, etc.) electrolytic capacitors and replace them and any circuit board damage. Also, check for any burnt or otherwise damaged components. The capacitors can be purchased on line for under 25 cents each. As a side note, defective capacitors were unwittingly used by some auto manufacturers for a few years, but Lexus was not one of them. A Google search will reveal more information.
Good Luck with your car….