Go Back   Club Lexus Forums > Lexus Model Forums > LS Models > LS400
Sign in using an external account
Register Forgot Password?

All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)

Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old 09-23-12, 06:20 PM   #16
Yamae
Lexus Test Driver
Trader Score: (0)
 
Join Date: Aug 2011
Location: Japan
Posts: 902
Default

I must add some. In the past, I have fixed different ECUs and what I can say is that you have to be very careful for selecting the electrolytic capacitors. The internal impedance or the ESR is the key to select. The capacitance value was not very strict. Sometimes +200% did not cause any problem. For an example, I have used 100uF instead of 47uF and it was fully OK. But when I have used a regular type of capacitor, it did not fix some problem.

Those who could not succeed or who are about to fix the ECU, I suggest you to use low ESR type capacitors such as Rubycon type ZLH, Nippon Chemicon KZH, Panasonic EEU and other equivalents.
This ad is not displayed to registered members.
Register your free account today and become a member on Club Lexus!

Last edited by Yamae; 09-24-12 at 04:11 PM..
Yamae is offline   Reply With Quote
Old 09-24-12, 09:35 AM   #17
wes619ls
Driver School Candidate
Trader Score: (0)
 
Join Date: Sep 2012
Location: CA
Posts: 10
Default

ordered the capacitors today $10 10 pieces rubycon zlh
Thanks for the info
wes619ls is offline   Reply With Quote
Old 09-24-12, 10:24 AM   #18
LScowboyLS
Lexus Champion
Trader Score: (0)
 
LScowboyLS's Avatar
 
Join Date: Dec 2011
Location: Birmingham, AL
Posts: 4,067
@vatoloco
Send a message via Yahoo to LScowboyLS
Default

where did you get all six (4 different capacities & voltages) for only $10?
LScowboyLS is offline   Reply With Quote
Old 09-25-12, 07:54 AM   #19
tommyb210
Driver School Candidate
Trader Score: (0)
 
Join Date: Sep 2012
Location: NC
Posts: 7
Default

could changing these help if i have a power drain from somewhere? if the car sits for 2 days its completely dead. brand new alternator and battery.
tommyb210 is offline   Reply With Quote
Old 09-25-12, 11:44 AM   #20
wes619ls
Driver School Candidate
Trader Score: (0)
 
Join Date: Sep 2012
Location: CA
Posts: 10
Default

**** ok so there's 4 different capacitors with 4 different voltages? I ordered a set of 10 pieces of rubycon zlh 1000uf 25v, what others do i need?
wes619ls is offline   Reply With Quote
Old 09-25-12, 04:36 PM   #21
LScowboyLS
Lexus Champion
Trader Score: (0)
 
LScowboyLS's Avatar
 
Join Date: Dec 2011
Location: Birmingham, AL
Posts: 4,067
@vatoloco
Send a message via Yahoo to LScowboyLS
Default

Quote:
ok so there's 4 different capacitors with 4 different voltages? I ordered a set of 10 pieces of rubycon zlh 1000uf 25v, what others do i need?
which caps you need and how many depends on the year model of your LS400

1995-97 LS400 needs 6 caps as follows:

Qty. 2 of 10uF - 50v
Qty. 1 of 47uF - 63v
Qty. 2 of 100uF - 10v
Qty. 1 of 220uF - 25v


not sure what you need the 1000uF caps for? - who told you to purchase that size?
LScowboyLS is offline   Reply With Quote
Old 09-26-12, 05:01 PM   #22
wes619ls
Driver School Candidate
Trader Score: (0)
 
Join Date: Sep 2012
Location: CA
Posts: 10
Default

I cancelled the order I have a 91, there's actually a store in San Diego I can walk in and buy them called Willy's Electronics.
wes619ls is offline   Reply With Quote
Old 09-28-12, 04:17 AM   #23
steve2006
Lead Lap
Trader Score: (0)
 
Join Date: Jan 2007
Location: UK
Posts: 676
Default

Sorry technical question, were the original capacitors in the ECU rated at 85 or 105 degrees?
Are the affected capacitors coupling or decoupling?
I assume as the capacitors age their ESR increases and capacitance decreases which in turn produces more heat and the cycle continues until the heat causes the plug to push out of the base and the electrolyte then leaks from the capacitor.
I normally use a product called 'Safewash" which is a water based foaming PCB cleaner that does not leave any residue then use the iso alcohol drying off with a hair dryer.
Thankfully I still have supplies of lead solder and don't have to use the leadfree substitute which is rubbish.
steve2006 is offline   Reply With Quote
Old 09-28-12, 05:26 PM   #24
LScowboyLS
Lexus Champion
Trader Score: (0)
 
LScowboyLS's Avatar
 
Join Date: Dec 2011
Location: Birmingham, AL
Posts: 4,067
@vatoloco
Send a message via Yahoo to LScowboyLS
Default

the original capacitors are 105C, but far more important than temp rating is that the replacement caps are LOW ESR type!

I recommend 63/37 leaded solder for this job, and the safewash is fine but not necessary, vinegar and a soft toothbrush will clean the board safely as long as you follow that with a distilled water wash and then a couple of 91% iso-propyl alcohol washes

make sure you use one of the big Japaense cap brands - Rubycon type ZLH, Nippon Chemicon KZH, Panasonic EEU or Nichicon low ESR

inspect your work with a loupe afterwards

should be 6 or 7 caps depending on your model year, higher voltage caps than original are not necessary, but fine to use!

BE CAREFUL with the 4 ribbon cables that attach the two mainboards

ALSO - keep in mind that the capacitors do not have to be visibly leaking to be bad, therefore you want to replace ALL of them, even if they look fine!

Last edited by LScowboyLS; 10-18-12 at 07:59 AM..
LScowboyLS is offline   Reply With Quote
Old 09-28-12, 09:15 PM   #25
1JZPWRD
1JZ Single SC400
Trader Score: (58)
 
1JZPWRD's Avatar
 
Join Date: Jan 2009
Location: Alabama, Roll Tide!
Posts: 8,468
Default

Thanks for the write up on this matter. Seems to happen a lot on the LS400's and not so much on the SC's. It does happen but it seems more often on the LS's..
__________________
1992 SC400, Sleeper..522RWHP - 93 octane, 1JZ, BW S366, Soarer R154, ACT Stage 4, 800cc, DM LW Flywheel, MINZ FPR, 3" Exhaust, HKS CF Slip on, HKS BOV, Tial 44 WG, BC 264 Cams, AEM gauges, AEM V2, MKIV Auto LSD!
Follow my build thread.....http://www.clublexus.com/forums/buil...and-links.html
Jay's Interior....http://www.clublexus.com/forums/sc-4...y-1jzpwrd.html
1JZPWRD is offline   Reply With Quote
Old 10-02-12, 02:22 PM   #26
cndnate
Driver School Candidate
Trader Score: (0)
 
Join Date: Mar 2012
Location: Michigan
Posts: 31
Default

Quote:
Originally Posted by LScowboyLS View Post
which caps you need and how many depends on the year model of your LS400

1995-97 LS400 needs 6 caps as follows:

Qty. 2 of 10uF - 50v
Qty. 1 of 47uF - 63v
Qty. 2 of 100uF - 10v
Qty. 1 of 220uF - 25v
Does anyone know off hand what capacitors I need for a 1993 Lexus LS400?

I would like to order them before taking apart ecu, and do it in one go. I plan to do the dash capacitors at the same time - does anyone know their part numbers?

Thank you!
cndnate is offline   Reply With Quote
Old 10-02-12, 02:33 PM   #27
Lavrishevo
Lexus Champion
Trader Score: (1)
 
Lavrishevo's Avatar
 
Join Date: Jan 2012
Location: Atlanta, GA
Posts: 2,320
Default

+1 I would vote that this be added to the FAQ sticky. Maybe someone would be kind enough to break down how many, which type, and recommended brands to be saved in the first post.
__________________
2004 LS430 UL
1999 LS400
Lavrishevo is offline   Reply With Quote
Old 10-03-12, 11:46 AM   #28
LScowboyLS
Lexus Champion
Trader Score: (0)
 
LScowboyLS's Avatar
 
Join Date: Dec 2011
Location: Birmingham, AL
Posts: 4,067
@vatoloco
Send a message via Yahoo to LScowboyLS
Default

here is the list of caps for 98-2000 models:

Qty. 2 of 10μF/50V
Qty. 2 of 47μF/63V
Qty. 2 of 100μF/10V
Qty. 1 of 220μF/16V
Qty. 1 of 33μF/35V
Qty. 1 of 47μF/25V
Qty. 1 of 330μF/35V


I am still working up a list of capacitors for the 1990-94 models

Last edited by LScowboyLS; 10-08-12 at 07:13 AM..
LScowboyLS is offline   Reply With Quote
Old 10-05-12, 12:08 AM   #29
LScowboyLS
Lexus Champion
Trader Score: (0)
 
LScowboyLS's Avatar
 
Join Date: Dec 2011
Location: Birmingham, AL
Posts: 4,067
@vatoloco
Send a message via Yahoo to LScowboyLS
Default

please remember, when servicing the ECU caps, these 4 critical points:

1. replace ALL of the electrolytic capacitors, even the ones that appear to be fine, they don't have to be obviously leaking to be bad - there are typically only 6 or 7 in total - the 98-00 models have 10.

2. make sure the caps you use are LOW ESR type and 105C rated and voltage is at least the original rating.

3. stick with high end Japanese caps - Rubycon, Nippon Chemicon, Panasonic, Nichicon.

Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.Click the image to open in full size.


4. be very careful with the 4 ribbon cables that attach the two mainboards, if one of these comes partially loose then you have created yourself a lot more work.

Last edited by LScowboyLS; 10-21-12 at 11:04 AM..
LScowboyLS is offline   Reply With Quote
Old 10-05-12, 10:29 AM   #30
53bel
Driver School Candidate
Trader Score: (0)
 
Join Date: Oct 2012
Location: Virginia
Posts: 51
53bel
Default

Model: 94 LS400
So i dont assume right now the 6 caps that are needed for 95 and up ordered from nippon, etc would be enough to order until the write up is done? i would like to do the dash and ECU at the same time again thanks for the help everyone.
Qty. 2 of 10uF - 50v
Qty. 1 of 47uF - 63v
Qty. 2 of 100uF - 10v
Qty. 1 of 220uF - 25v
53bel is offline   Reply With Quote
Old 10-05-12, 10:29 AM
 
 
 
 
Reply

Tags
1996, 400, auto, capacitors, chicago, defog, ecm, ecu, flashing, light, ls, ls400, replace, replacing, service

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
how to check your ECU without removing it from car - by Yamae LScowboyLS LS400 11 07-28-14 06:56 PM
I just purchased a 1996 LS400 with 218XXX Miles. Maintenance Advice? I have a list! BeLSNow111 LS400 28 02-04-14 09:02 AM

All times are GMT -7. The time now is 09:40 PM.

Join ClubLexus
Advertising


Copyright © 2000-2008 Internet Brands, Inc. All Rights Reserved
Privacy Policy | Disclaimer | Terms of Use | JOBS


Get all contact info