My 94 Lexus SC300 started intermittently running very badly a couple of weeks ago. It would set codes, go into what I surmised was 'limp home' mode where it ran pig rich, wouldn't idle, and generally behaved badly.
After some troubleshooting, I narrowed it down to the ECM itself and brought it in to work today. The ECM has a bunch of electrolytic capacitors that had overheated and failed, corroding the board under them. Here's a pic of the worst one, under magnification:
Thanks to a talented micro-min solder tech who works with me, it's repaired and I drove it home tonight. The trace and one pad for the cap were gone, along with an adjoining trace. He soldered 30 ga. wire over the breaks, including forming the wire into a loop for one leg of the cap. He then soldered the cap to the wire loop as well as the other side of the board. Beautiful job and beyond my soldering skills, for sure! It's good to have friends. :-)
I don't know what that job would've cost to have somebody else troubleshoot and source an ECM. More than the car's worth, for sure. 206k miles and it purrs like a kitten, though.
