All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)
#1816
Driver School Candidate
Thanks LScowboyLS and Yamae
Joined the forum to thank the originators of this thread, after putting >$2000 into my son's '95 LS400 with a decent local shop without fixing the problems, I spent 20 bucks mostly shipping with DigiKey and Mouser and a day relearning soldering to replace the caps (one had leaked and I feared some traces were gone, but went ahead as no loss), and car now running like a Japanese watch.
Thanks again LS and Yamae. Best of the net to you!
Thanks again LS and Yamae. Best of the net to you!
#1817
Driver School Candidate
LScowboyLS, Thank you SO much for this information. I have several Gen 1 SC's, and your and Yamae's work helped me with finding my problems. I had Tanin repair 2 ECU's and SIA electronics another. I also find this problem in the Nakamichi power amplifiers. Thanks Again!!!!!!
ps: I don't know what the spoiler function is, and can't seem to get rid of it. Sumimasen!
ps: I don't know what the spoiler function is, and can't seem to get rid of it. Sumimasen!
Last edited by RA40; 03-23-22 at 01:33 PM. Reason: Apologize for "spoiler" function-edited
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dhood (05-04-22)
#1819
Lexus Test Driver
As someone who repairs high end foreign industrial electronics as part of my job I think that price is excellent.
The only way it can be done professionally & reliably at that price is if someone is set up for working on that exact item.
The only way it can be done professionally & reliably at that price is if someone is set up for working on that exact item.
#1820
Driver School Candidate
Joined: May 2003
Posts: 11
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From: Tennessee
Soldered screwheads on lower board
Regarding the residue I worry that there is a capillary action.
https://www.youtube.com/watch?v=JK-GONTd9U8&t=19s
Regarding the electrolytic capacitors, you can't judge the condition by human eyes. Check them using an ESR meter. If it's not available, replace capacitors printed Nichicon PR(M), PF(M) ot PL(M) unconditionally. Those contain the QAS liquid and are a kind of time bomb. Leaked or not leaked yet, simply replace them for your happiness.
https://www.youtube.com/watch?v=JK-GONTd9U8&t=19s
Regarding the electrolytic capacitors, you can't judge the condition by human eyes. Check them using an ESR meter. If it's not available, replace capacitors printed Nichicon PR(M), PF(M) ot PL(M) unconditionally. Those contain the QAS liquid and are a kind of time bomb. Leaked or not leaked yet, simply replace them for your happiness.
Thanks for any help.
#1821
Hello LScowboyLS and Yamae, I'm in awe of this thread and the wealth of information you've so diligently provided. I've gotten into some trouble.
>>>> I'm in desperate need of at least one(1), or four(4), of the 47uF and at least one(1), or two(2), the 220uF<<<<
I had followed the recommended parts list and put the various items, and alternates, into my shopping cart at digikey. Sadly, I failed to confirm the order in time and 2 of the needed capacitors are now on backorder(at mouser, too). (I had only realized my error after wondering why the package hadn't arrived after 2 weeks) I have no clue as to how to identify what is, or is not, a" Low-ESR" capacitor. (and have failed at 'Google University' on this subject)
Could you please Help me identify alternatives?
Sincerely
>>>> I'm in desperate need of at least one(1), or four(4), of the 47uF and at least one(1), or two(2), the 220uF<<<<
I had followed the recommended parts list and put the various items, and alternates, into my shopping cart at digikey. Sadly, I failed to confirm the order in time and 2 of the needed capacitors are now on backorder(at mouser, too). (I had only realized my error after wondering why the package hadn't arrived after 2 weeks) I have no clue as to how to identify what is, or is not, a" Low-ESR" capacitor. (and have failed at 'Google University' on this subject)
Could you please Help me identify alternatives?
Sincerely
#1822
Hello LScowboyLS and Yamae, I'm in awe of this thread and the wealth of information you've so diligently provided. I've gotten into some trouble.
>>>> I'm in desperate need of at least one(1), or four(4), of the 47uF and at least one(1), or two(2), the 220uF<<<<
I had followed the recommended parts list and put the various items, and alternates, into my shopping cart at digikey. Sadly, I failed to confirm the order in time and 2 of the needed capacitors are now on backorder(at mouser, too). (I had only realized my error after wondering why the package hadn't arrived after 2 weeks) I have no clue as to how to identify what is, or is not, a" Low-ESR" capacitor. (and have failed at 'Google University' on this subject)
Could you please Help me identify alternatives?
Sincerely
>>>> I'm in desperate need of at least one(1), or four(4), of the 47uF and at least one(1), or two(2), the 220uF<<<<
I had followed the recommended parts list and put the various items, and alternates, into my shopping cart at digikey. Sadly, I failed to confirm the order in time and 2 of the needed capacitors are now on backorder(at mouser, too). (I had only realized my error after wondering why the package hadn't arrived after 2 weeks) I have no clue as to how to identify what is, or is not, a" Low-ESR" capacitor. (and have failed at 'Google University' on this subject)
Could you please Help me identify alternatives?
Sincerely
47uF 63V
https://www.digikey.com/en/products/...6-3X11/3134467
220uF 16V
https://www.digikey.com/en/products/...6-3X11/3563156
https://www.digikey.com/en/products/...6-3X11/9553861
https://www.digikey.com/en/products/...1MF11D/3529147
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dhood (05-04-22)
#1823
It has been a decade since LScowboy and I had talked on the phone discussing about the ECU failing problems and started a new thread. He said, "This gonna be a big thread". I never thought so but it actually was and there still come people and ask us. Unfortunately LScowboy is not here anymore and I have to do some instead of him.
A decade is long enough to change things and the availability of capacitors were also affected. The list we made is getting old and some of capacitors are not available or obsolete. There also started to sell newer capacitors by major capacitor manufacturers. There come people who still need to change capacitors saying that some capacitors are not available. This time I understood that 2 capacitors were not OK to purchase. If there are other capacitors like those, inform me.
It would be the best to make a totally new list but currently I am busy doing things a lot as a chairman of a local community leaders and a helper who is still often called by local auto shops and dealers. I happen to speak Spanish and English some and there come requests to help foreign people living around here too. COVID 19 sure made an old man to run. So if there are no availability problems of some particular capacitors, please let me know. I'll try to find alternative ones.
A decade is long enough to change things and the availability of capacitors were also affected. The list we made is getting old and some of capacitors are not available or obsolete. There also started to sell newer capacitors by major capacitor manufacturers. There come people who still need to change capacitors saying that some capacitors are not available. This time I understood that 2 capacitors were not OK to purchase. If there are other capacitors like those, inform me.
It would be the best to make a totally new list but currently I am busy doing things a lot as a chairman of a local community leaders and a helper who is still often called by local auto shops and dealers. I happen to speak Spanish and English some and there come requests to help foreign people living around here too. COVID 19 sure made an old man to run. So if there are no availability problems of some particular capacitors, please let me know. I'll try to find alternative ones.
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dhood (05-04-22)
#1825
#1826
Hello everybody,
I need to replace my SMD aluminum electrolyte capacitor in my ECU car with 35V 220uF. This capacitor is manufactured by Vishay. It is 150CRZ type. Data sheet is here. There are two types for my application which are one and two. One has higher ripple current than two (630 mA VS 409.5 mA). From this, I prefer the type one.
I tried to search in digikey and compare the same capacitors with the same voltage and capacitance. The vishay is the most expensive than the others. Why? Does it mean it has better quality? Rubycon here is better in lifetime and low impedance with lower price. Any other suggestions? Any suggestions will be appreciated.
I need to replace my SMD aluminum electrolyte capacitor in my ECU car with 35V 220uF. This capacitor is manufactured by Vishay. It is 150CRZ type. Data sheet is here. There are two types for my application which are one and two. One has higher ripple current than two (630 mA VS 409.5 mA). From this, I prefer the type one.
I tried to search in digikey and compare the same capacitors with the same voltage and capacitance. The vishay is the most expensive than the others. Why? Does it mean it has better quality? Rubycon here is better in lifetime and low impedance with lower price. Any other suggestions? Any suggestions will be appreciated.
Last edited by Nuro; 05-15-22 at 07:53 PM. Reason: previous one is too long
#1827
ECU issues possible on a 98 LS4?
I have a 98 LS400 with 102k miles and have recently had the following problems that I am thinking might be ECU cap related.
ODO recently reset from 102k to 3800 miles!! Given its a low mileage car already, this is concerning (not that I plan to ever sell this baby)
About half the time the RPM gauge reads high and inaccurate (like 5k rpm at idle, redlined at highway speeds)
The same for MPH, reads about 3x the correct speed (although it is hilarious to do 65 and have it read 160mph
AC has developed a whine that increases with RPM and is only cool (no longer cold)
Shifting from 1st to 2nd is a tad delayed, no other performance issues car runs amazingly otherwise.
I am reading through this thread that 98-00 LS400s do not often have the ECU cap problem. Is that correct?
Finally, I really have no desire or skill to perform the cap replacement so what are my options? Ideally I would prefer to pay someone locally to do the whole thing (Kansas City area) or alternatively I can try and remove the ECU and send it off. Who is the trusted and preferred clublexus ECU repair vendor?
Thank you.
ODO recently reset from 102k to 3800 miles!! Given its a low mileage car already, this is concerning (not that I plan to ever sell this baby)
About half the time the RPM gauge reads high and inaccurate (like 5k rpm at idle, redlined at highway speeds)
The same for MPH, reads about 3x the correct speed (although it is hilarious to do 65 and have it read 160mph
AC has developed a whine that increases with RPM and is only cool (no longer cold)
Shifting from 1st to 2nd is a tad delayed, no other performance issues car runs amazingly otherwise.
I am reading through this thread that 98-00 LS400s do not often have the ECU cap problem. Is that correct?
Finally, I really have no desire or skill to perform the cap replacement so what are my options? Ideally I would prefer to pay someone locally to do the whole thing (Kansas City area) or alternatively I can try and remove the ECU and send it off. Who is the trusted and preferred clublexus ECU repair vendor?
Thank you.
#1828
I have a 98 LS400 with 102k miles and have recently had the following problems that I am thinking might be ECU cap related.
ODO recently reset from 102k to 3800 miles!! Given its a low mileage car already, this is concerning (not that I plan to ever sell this baby)
About half the time the RPM gauge reads high and inaccurate (like 5k rpm at idle, redlined at highway speeds)
The same for MPH, reads about 3x the correct speed (although it is hilarious to do 65 and have it read 160mph
AC has developed a whine that increases with RPM and is only cool (no longer cold)
Shifting from 1st to 2nd is a tad delayed, no other performance issues car runs amazingly otherwise.
I am reading through this thread that 98-00 LS400s do not often have the ECU cap problem. Is that correct?
Finally, I really have no desire or skill to perform the cap replacement so what are my options? Ideally I would prefer to pay someone locally to do the whole thing (Kansas City area) or alternatively I can try and remove the ECU and send it off. Who is the trusted and preferred clublexus ECU repair vendor?
Thank you.
ODO recently reset from 102k to 3800 miles!! Given its a low mileage car already, this is concerning (not that I plan to ever sell this baby)
About half the time the RPM gauge reads high and inaccurate (like 5k rpm at idle, redlined at highway speeds)
The same for MPH, reads about 3x the correct speed (although it is hilarious to do 65 and have it read 160mph
AC has developed a whine that increases with RPM and is only cool (no longer cold)
Shifting from 1st to 2nd is a tad delayed, no other performance issues car runs amazingly otherwise.
I am reading through this thread that 98-00 LS400s do not often have the ECU cap problem. Is that correct?
Finally, I really have no desire or skill to perform the cap replacement so what are my options? Ideally I would prefer to pay someone locally to do the whole thing (Kansas City area) or alternatively I can try and remove the ECU and send it off. Who is the trusted and preferred clublexus ECU repair vendor?
Thank you.
The main ECU is only getting the result of the calculation.
Using an oscilloscope or a pulse counter I'd observe the speed signal line coming from the ABS & TRC & VSC computer to the cluster unit first before jumping to the main ECU. When the pulses are OK, the speedometer/odometer problem must be related to the cluster unit. The ABS & TRC & VSC computer is averaging of 48 pulses from 4 ABS sensors and then divides the value and send the calculation result to the cluster unit.
Regarding to the delayed engagement from 1st to 2nd gear, I'd rather think it's not the ECU issue but the pressure issue or the clutch issue. If I were you, I'd do the pressure check first using an SST.
Adapter to check AT's line pressure
Anyway, your problems need to use measuring tools to find out the root cause(s).
Last edited by Yamae; 05-21-22 at 07:38 AM. Reason: To add the pressure check
#1829
Update ... SUCCESS! Thank You!
Don't worry, my friend. These should work.
47uF 63V
https://www.digikey.com/en/products/...6-3X11/3134467
220uF 16V
https://www.digikey.com/en/products/...6-3X11/3563156
https://www.digikey.com/en/products/...6-3X11/9553861
https://www.digikey.com/en/products/...1MF11D/3529147
47uF 63V
https://www.digikey.com/en/products/...6-3X11/3134467
220uF 16V
https://www.digikey.com/en/products/...6-3X11/3563156
https://www.digikey.com/en/products/...6-3X11/9553861
https://www.digikey.com/en/products/...1MF11D/3529147
#1830
Mildly terrifying
My 93 ls400 (1uz) has been experiencing a hefty chunk of these issues i believed it was a simple short in the harness because some mice did a number on some wires so I electrical taped em to cover any exposed wires but the issues continued I engaged my parking break once and since that time the light has remained on this could be due to a break in the line (rear brakes have issues) but it would trigger with acceleration and turn off on breaking or coasting along with my tach reading 0 on idle but coming up with throttle when it works (could just need to be adjusted) and the speedometer reads about 10 slow again when it works could be the same as tach I'm also triggering my main o2 sensor and earlier today the reason why I'm here and seriously considering this could be my issue coming through my town I was experiencing the eradic idle and an extreme bog upon accelerating from a stop then on one stop i idled fine and got my chance to turn and it stalled out I was unable to start it for about 20 minutes I'd get 2-4 cylinders to fire once and it'd stop again so I pushed it to a parking spot waited and had to neutral start it and give it gas to keep it alive I limped it home through two foot using neutral to keep it revving until takeoff
i Know this was a long one just asking if anyone has had similar patterns caused by this issue
i Know this was a long one just asking if anyone has had similar patterns caused by this issue