of my LS400 tranny is acting VERY weird! (UCF20/21)
#16
Moderator
Most of them were spending extra money for many parts as well as the ECU. The shop owner asked me to help and I found electrolytic capacitors were not holding enough capacitance as well as the ESR was increased.
Replacing them to low ESR electrolytic capacitors fixed the problems next to next. That was the beginning of the story.
A little later on, I found several owners here at Club Lexus having the same problem and I suggested them to replace those capacitors. There were no quick responses but all of the sudden you Cowboy replied me.
I'd say most of junk yard LS400 except collision cars were sent there because poor mechanics could not fix the problem. Those deteriorated capacitors may be beyond their understandings. Modern cars are equipped with many electronics devices but many of mechanics are not very familiar to those. Also many car owners are the same. Someone like you can help many people, Cowboy. If I were fluent enough in English, I also could help them more.
#17
Driver School Candidate
Thread Starter
Join Date: Aug 2013
Location: WA
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Pulled out the ECU, disassembled it, and found 3 brunt capacitors. sadly I didn't have the cam at that time. but will keep you posted once I get it fixed by evening!
hopefully the transmission problem get solved, and if not, at least I will be able to read the error code.
that explains everything, the car was stored for 2 years without moving! we'll see how it runs after it's fixed.
hopefully the transmission problem get solved, and if not, at least I will be able to read the error code.
besides, a junkyard ECU would also need its capacitors replaced, so that doesn't really help you!
#18
Lexus Champion
Pulled out the ECU, disassembled it, and found 3 brunt capacitors. sadly I didn't have the cam at that time. but will keep you posted once I get it fixed by evening!
hopefully the transmission problem get solved, and if not, at least I will be able to read the error code.
that explains everything, the car was stored for 2 years without moving! we'll see how it runs after it's fixed.
hopefully the transmission problem get solved, and if not, at least I will be able to read the error code.
that explains everything, the car was stored for 2 years without moving! we'll see how it runs after it's fixed.
please use the links to the correct capacitors in post #1 of our ECU capacitor thread
Last edited by LScowboyLS; 09-03-13 at 04:55 AM.
#19
Driver School Candidate
Thread Starter
Join Date: Aug 2013
Location: WA
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
Capacitors where replaced with the Japanese one! made sure they're the correct order, the problem still persist! luckily there were another ECU in hands also suffered from brunt capacitors that were replaced with very same capacitors and WHAM!!! ALL PROBLEMS GONE!! it ran fine again!!
perhaps my ECU suffered from a short circuit???
perhaps my ECU suffered from a short circuit???
#21
(and if I am wrong here, I am sure Yamae will correct me )
#22
Lexus Champion
yes, vehicles that have sat a lot (like low mileage, snowbird-owned LS400's) are particularly afflicted with the ECU capacitor issues, though it eventually affects all LS400 models, as Yamae advises, though 98 and later have a better tolerance for it, so 98-00 models will be affected in the future more than today
#23
Moderator
You can find the detail at the middle part of http://en.wikipedia.org/wiki/Capacitor.
I just picked up the related part from there.
Electrolytic failure from disuse
Electrolytic capacitors are conditioned when manufactured by applying a voltage sufficient to initiate the proper internal chemical state. This state is maintained by regular use of the equipment. If a system using electrolytic capacitors is unused for a long period of time it can lose its conditioning, and will generally fail with a short circuit when next operated, permanently damaging the capacitor. To prevent this in tube equipment, the voltage can be slowly brought up using a variable transformer (variac) on the mains, over a twenty or thirty minute interval. Transistor equipment is more problematic as such equipment may be sensitive to low voltage ("brownout") conditions, with excessive currents due to improper bias in some circuits.
Thread
Thread Starter
Forum
Replies
Last Post
FireCode
Performance & Maintenance
17
07-26-20 08:22 AM
allen
LS - 1st and 2nd Gen (1990-2000)
2
11-08-04 01:03 PM