All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)
Anyway, congratulations on your successes. It 's also a big success for you that your son became a master of two different degrees. He must have studied hard but without your assistances, he couldn't be that big, I can imagine easily. You really are a good father.
If this is really LVC, then I owe you a double dose of thanks - once for the help and info with the ECU, and secondly for the many, many movies! I always knew we were in for a rollicking good time if you were featured!!! So, Thank You!
Thanks for all the information posted thus far and for the information I hope to receive!!
Thanks for all the information posted thus far and for the information I hope to receive!!
Thanks for all the information posted thus far and for the information I hope to receive!!
as Yamae recommended, order as cowboy suggested below for me '93sc400.
3 of 10uF
2 of 15uF
3 of 47uF
2 of 100uF
1 of 220uF
i rebuilt my ecu last month using above caps from digi-key. u will have a couple spares but
to be safe go with above. my total cost was barely $10 including shipping.
btw.. been a month since i replaced caps and car is running beautifully
Thanks
SC93, thanks for also helping out and verifying the correct ones to get.
Last edited by dhhd; Oct 5, 2013 at 05:59 AM. Reason: more appreciation to give ;)
Celebrating Lexus & Toyota from Around the Globe
problem: transmission jerks from 1st to 2nd gear, and kinda slips from 2nd to 3rd.
solution: changed capasitors on the ECU (11 pieces total).
car: LS400 1998 UCF20 (european model, coz I´m in europe).
result: problem solved !!!!!!!!!!!
costs: quite a lot, because of the shipping costs, but its worth it !!
NB! Old capasitors didnt show any sigh of leaking or anything, they looked like new, but obviously didnt do their work good any more.
Special thanks goes to LScowboyLS for helping me with the capacitors ... and Yamae for sharing usefull information !!
Thanks
SC93, thanks for also helping out and verifying the correct ones to get.
Last edited by LScowboyLS; Oct 5, 2013 at 10:57 AM.
problem: transmission jerks from 1st to 2nd gear, and kinda slips from 2nd to 3rd.
solution: changed capasitors on the ECU (11 pieces total).
car: LS400 1998 UCF20 (european model, coz I´m in europe).
result: problem solved !!!!!!!!!!!
costs: quite a lot, because of the shipping costs, but its worth it !!
NB! Old capasitors didnt show any sigh of leaking or anything, they looked like new,
but obviously didnt do their work good any more.
Special thanks goes to LScowboyLS for helping me with
the capacitors ... and Yamae for sharing usefull information !!
Thanks for the detailed report from North East Europe.
Your report will tell something very important to owners who own UCF20/21 of model year 1998 or after. Those models were still in use of Nichicon PF(M) and PR(M) capacitors that containing "quaternaty ammonium salt " and are quite risky to use many years.

One of the important points is that it was rather a AT related symptom than the engine.
This is another example of the failing ECUs for UCF20 related to AT to me. One more important point is that the problem has happened at the cooler climate place there in Estonia, Europe.
Denso and Toyota redesigned the ECU for the VVTi engine of 1UZ-FE, using newer processors that consume less energy and this reduced the loads for the DC-DC converter in the ECU.
Also newer ceramic capacitors were used there in parallel with the Nichicon capacitors. These do not stress electrolytic capacitors used at the DC-DC converter compared with former generations. Thus, models after 98 have less opportunity to have failed electrolytic capacitors. But those are still Nichicon PF(M) and PR(M) capacitors and you'd better not to think safe.
It has been 16 years since 98 models (manufactured after July 1997) were shipped, those Nichicon capacitors are also aged and it is natural to fail these days. Most of users and mechanics consider that the problem may be caused by the aged mechanical parts inside of the AT but the fact is not always so. The overhaul of an AT is not a simple and easy job but replacing capacitors is easy and the cost is much less. My Celsior is a 98 and I already have replaced the Nichicon capacitors 2 years ago and I will not be messed up my AT unit by an AT technician.
I had the transmission problem since I have bought the car 4 years ago.
As I said earlier, I have changed capacitors and the problem got solved.
Yesterday I checked the old capacitors, and only one had visual defects. I´m not a specialist, but check out the 3 bubbles on the top.







