Gavincwsc4

Does anybody have any pictures of a 93 sc400 ecu opened up do ican see which cap goes where ? Mine was so bad that multiple caps were just rattling around in it itd be much appreciated bc im stuck until I get it done car wont even run right now

Yamae

Since this is a LS400 Forum and there are not many people who are familiar to SC400.
I don't know it matches to your needs or not but this page has 5 photos of a 92-94 SC400 ECU.
https://www.justparts.com/Auto_Parts...UZ-FE/32639074

scrapp

I created this CL account probably 13 or something years ago, yet have never had an opportunity to own a Lexus.

So if you would excuse the cobwebs for my first ever post, i haven’t cleaned up, but I just had to log on after all these years just so I could tell some complete strangers Thank you for keeping this information alive and updated.

Im very serious.
Cowboy, Yamae, thank you for the effort you two have put into this information years ago that can easily be found in google. Ive been lurking over this information for a month now, and I finally decided to do everything exactly as you said, I bought exactly as you said and my issue is completely gone.

My weird fuel cut at 4k rpm when more than half throttle completely disappeared.

Don’t get me wrong, I have an actual history of soldering experience, but I have never tried so hard to succeed at something as much as making sure I dont destroy a Lexus ECU. I would consider this a bucket list accomplishment

Again I say Thank You (I am IMMENSELY serious) for the help and knowledge you passed on to me,
I am now the *much relieved* new owner of a 93 LS400 (w/ 1uzfe swap from a Hi-Ace Ambulance, I think??) with a $4 fix.


Be excellent and party on, dudes.

mr2j

Hi ClubLexus. Let me start off by saying I think it's great so many people take their time to post on here, Ive gotten a lot of help and info from here.
So I was in the middle of a interior swap on my 99 SC300. I would move it in and out of the garage during the process and all was well. One day, it started misfiring and running crazy rich with a ton of white smoke shortly after startup. I borrowed my buddys ecu (and key) and it ran totally fine and clean after about 20 minutes of clearing out all the fuel and what not I assume. So I went ahead and opened up my ECU then ordered the appropriate capacitors from this thread (all 8). I had a OK time installing them. After I installed the ecu, the car would only crank and not start. The ETCS would sometimes come on, sometimes not. The security light would also sometimes come on and sometimes not with the key in the run position. I will post pictures soon, but where should I start? Any tips or ideas would be greatly appreciated. Thank you!

mr2j

Also, I would like to add everything looked fine inside and I saw no obvious signs of capacitor failure.

Richard14

That's very interesting slot of these are the issues with my rx300. I wonder if maybe this could be the culprit.

RA40

iTrader: (6)

Unlikely. One of the symptoms for the failing capacitors in these older cars is the lack of codes and poor running. Replace the OCV/oil control valve and knock sensor in yours. Check that the vacuum lines are also snug and not split at their connection points.

GenericUse

God, I hate the "related thread" crap at the bottom of the page. Anyway, does anyone in THIS thread know where to get a refurb ECU? Mine's not repairable. I've seen them on Flagship One and such but that site has terrible reviews.

TaninAuto

We stock some ecus. Can get others. Not sure what model you need.

Lepsus

Hey all first time posting here and big thanks for this thread LScowboyLS and Yamae + everyone else!
Few months ago i bought some caps from digi-key without openin ECU first, but now i had finally time to open it. I noticed that my ecu has 9 caps instead of 6 (1997 LS) Luckily can't see any leaks and earlier i bought some extra ones so im only missing two 15uf 35v caps.
ECU number: 89661-50310 and caps that i spotted:

1x 220µF 16v
2x 47µF 63v
2x 100µF 10v
2x 15µF 35v (i need buy these)
2x 10µF 50v

I assmume, i just use first post link to buy two 15µF 63v ? EKZE630ELL150ME11D

My car:
4D SEDAN LS400-UCF20L-AEPGKW/285
first time registered 9/1997 (Finland)

Problems that my car has:
random engine stalling after long highway trips (happens when i slow down enough and going to leave ramp or turn)
sometimes low rpm when i stop on lights while gear is on
sifting isn't smooth always
sometimes sulfur smell (rotten eggs) usually happens when i speed up to highway speeds

Now i need order last caps and find someone who is good at soldering.
sharing some pics of ecu and those caps in the bags that i have bought earlier. Also i wonder why there is green marker paint on those old caps?




9 caps total

moinhaider

Is there anyone here in the Asia Pacific region who can rebuild ECU's? I have a JDM 1995 Toyota Celsior UCF21 and wanted to take care of the issue as preventative maintenance.
Thanks!

GrapeDaddy

Hi everyone,

I'm looking for some detail photographs of a Celsior ECU. Specifically, 89661-50240. Cowboy has my ECU, but there is some considerable damage to the board. I wanted to see if someone who has one of these ECUs would be willing to open it up and take some detailed photographs of the lower board.

Thanks for any help on this!

Yamae

I only have a spare ECU for a 98 Celsior and sorry that I can't give you any.

One thing I'd better to inform you is that a 89661-50240 has an engine halt problem after the continuous high speed run and it would be better to use a 89661-50380 if available. But unfortunately old Celsiors are almost gone here in Japan and I don't see them at all. Regarding the halt problem, the same thing was happening among 95 LS400s and you can find more about the problem searching the Forum.

I myself am beginning to have difficulties to order some new parts even for a 98 Celsior. Owing an old Celsior often needs to spend hours and hours to obtain parts but it often ends with no luck. Many after market parts are not well made and they tend to fail rather quickly. Some of them aren't even fully compatible or usable.

Another important thing. JDM Celsiors use a hydraulic fan and the JDM ECU has functions to control it. This uniqueness makes it impossible to use an ECU for non hydraulic fan models. There may be a way to convert the cooling system or to modify the ECU if the owner or a mechanic is skilled and capable to do so.

GrapeDaddy

Hi Lepsus. It appears your ECU is very similar to my Japanese model. I wondered if you might be able to provide another photo?

The area in your photo looks identical to mine, pictured first. In my pictures, you can see the capacitor has leaked and caused damage to the traces on the board. Could you provide a couple pictures each of these areas on your ECU so that Lscowboyls might be able to repair mine?

moinhaider

Has anyone had experience with Relentless Motorsports in Texas? Seems like they are well versed in repairing old JDM ECU's. I am currently talking to someone there who's willing to take a look and fix any issues. Any feedback is much appreciated!