97celsior

Hello everyone, I've been following this thread for quite some time, while trying to find an expert who can do the caps replacement. Unfortunately I can't seem to find it, so I decided to try to do it myself.

But there is something that confuses me, the list in post 1 mentions that I need 6 caps. But I saw Yamae said in a post that my car (celsior 97 with ecu 89661-50380 ) requires 9. If anyone can help provide the correct type of the caps I will be very grateful 🙏

Yamae

Due to the difference of emission controls and regulations, early JDM UCF20/21 Celsiors have different ECUs compared with USDM LS400 models. You need to see the board and you will find 9 capacitors there.

hvTemCA

Hello all,
I wanted to remove the ECU from my 1994 LS400 to replace caps as suggested by LSCowboyLS in this thread (thank you and Yamae for the detailed information.) But my car does not have the lower glove box like in the diagram provided by LSCowboyLS (see the photo.) In place of the lower glove box is a panel (in addition to the bottom cover which I've already removed.) I found and removed 3 screws at the bottom of the panel but could not find other fasteners because it's in a very tight space so visual inspection is severely limited.

Does anyone have instructions and diagram to help me remove the panel? Thanks in advance.

Maxine400

ok so heres my question. I have a 96 ls 400 with about 295k that i just recently purchased. the issues im having is i cant seem to clear up the misfire codes i keep experiencing. heres the symtpoms. car start fines but runs rough, intiially when i first pull the codes i was getting misfires 2 and 4 and a random misfire code. so i did a basic spark plug and wire replacement it cleared the 4 misfire but the 2 remained. reading this thread i decided to do a ecu swap from a junkyard ecu and ended up with the same misfire code. i also replaced just the 2 cylinder spark plug because it was covered in carbon deposits and the new plug is comimg bac misfiring.... So what wud you suggest i check next???? Injectors???? ived ruled out the ecu at this point

hvTemCA

Found the way:
I opened the glove box, removed the felt layer (not as simple as it sounds.) Then I saw 2 screws that were covered by the felt. After removing the screws, I needed to use a little force to shake the panel and it got loose. I found the ECU attached to the panel by 3 nuts.

Yamae

I worry that the cam timing is off. The confirmation can be done observing waveforms of cam sensors and the crank sensor. Or check the timing belt set correctly removing the timing belt cover. I also have to add that sometimes the distributor is messed up inside.

DLfpv

I just changed my caps today as preventative maintenance on my 98. Here is the diagram I made with cap positions if anybody else with 98 needs it (May also match 99-00). I ordered my capacitors before the 1st post was updated to include the 220uf 16v part numbers and instead used Nichicon UHW1H221MPD, Is this okay? Should I order a 16v one and replace it?

LeX2K

Nothing wrong with using a 220uf 50 volt in place of the original.

Sleiggan

Hi!
First of I’d like to say thanks to everyone that have contributed to this thread, especially Yamae.
I’ve helped a friend on his 94 Toyota Supra, where the car just wasn’t running right. Missing on idle and loss of power.
So I found this thread, changed out the capacitors and now the car is running like a dream

But, the car has a separate “throttle control computer” used for traction control and the whole traction control system isn’t working. So we opened the throttle control computer and there were leaking caps.
The caps are:
47uF 63V
330uF 35V
100uF 10V
220uF 16V
10uF 50V x3
820uF 35V
I’ve found replacements for all of them on the first page except the 820uF one, and was wondering if someone could help me find a good replacement.
I found this: https://www.digikey.com/en/products/...C18X20/3134465
Is that a suitable replacement?

Thanks
Jesper

Yamae

Congratulations on your success. Thank you for the report. I can easily imagine that your friend is now very happy with your efforts and results. I'm glad that there comes another person who succeeded to revive the car. It's my pleasure too.

Although I haven't owned a Supra, I believe that it's suitable for your friend's Supra since it's a Rubycon ZLH series which I find the series very good for our applications and recommended as is written at the lower part of this post.

SAFSUCF10

Hello there everyone, I've got a 1992 Toyota Celsior and plan to replace the old caps on my 89661-50170 ECU


These are the capacitors I got as recommended by Yamae for a 1990-92 LS400. Bought them from digikey.com

I've sent the caps to an experienced electrician as I don't know anything about soldering whatsoever.
My ECU is a 89661-50170 model. I just want to make sure that if the ECU fix doesn't work, what ECU should I replace it with and where can I get them online?


89661-50170 ECU

Currently, this is the condition of my ECU (not looking too good if I might add)

A little history about the car is that it had one owner who kept the car in their garage since 2010. The car wouldn't start back then so they gave up and bought a more modern car.
Moving forward to 2022, I bought the car from the owner and brought it to the workshop. Got it working after 7 months in the workshop and brought it home. Car still starts and all that but it seldom lacked power and was just not consistent, had really low idle. At one point it couldn't start so I gave it a throttle body cleaning service. It also has other issues with the instrument cluster (some of the lights don' work, speedometer does not go up, lights only work on the needles etc.)

So, I looked around the Lexus forums and found this post. Judging from the picture of the ECU above - are there any other caps/resistors that I should replace? (looking at that blue one on the middle bottom left that looks corroded) If so, can anyone point me in the right direction on where I can get the caps for those? My plan is to fix the ECU first and sorta get a gauge of if the fix works or not and then focus on the instrument cluster after.

Yamae

Your ECU 89661-50170 has strange capacitors to my eyes. Those look like different capacitors that were used by Denso or our recommending capacitors if those were replaced.

Regarding the replaceable ECU, you can use a 89661-50171 instead of a 89661-50170. The firmware is a bit improved.

myztiic

Just replaced the caps in my 1993, totally worked!! No more high idle, no more CEL and failing to enter diagnostic mode, and many many more!!! was so excited when she fired up!!! Thank you for this!!!

ERK

This is the post I’ve been looking for. My kids 1990 LS400 is having a bunch of these same problems. Now I have something more to go on, thank you for this information.

Yamae

Some of early 1990 LS400 models have electrolytic capacitors manufactured by Marcon. Those use the shrink tube colored black and those are different from Nichicon's capacitors PR(M) or PF(M) with brown tubes. Which manufacture's capacitors does your car's ECU have inside?