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Hello all! I have a 1994 2nd gen Toyota celsior(non vvti). My current ecu is the 89661-50241. It has been refurbished once by Relentless with brand new capacitors as previously it had leaked completely. Car was running fine after the refurbishing. But ever since last year the performance of the car has dropped, gear shifting is hard, the AC vents blow uncontrollably sometimes and sometimes it works perfectly, I’ve had the car stall after long drives, the noise has increased a lot and in general it just feels very inconsistent. I got rid of the stalling issue, the cam shaft sensor wire harness was loose. Oh and my RPM on cold start is up to 1800 and takes a lot of time to get to 750.
now my question is would the 89661-50380 replacing the 89661-50241, help my case? I did buy one and tried to install it, when the car cranks, it sounds like metal on metal war is going on and it won’t start. Mechanic says the ecu is not for this car but on the system it shows it is. Now I have found a link to Toyota and they will send me a brand new 89661-50380 ecu, but it’s going to cost me 3k USD and I don’t know if I should take the plunge.
if Mr. @Yamae could chime in and give me some advise, that would be highly appreciated.
It is strange that your 94 Celsior has an ECU 89661-50241 which is used for a Celsior manufactured between Jan. 95 to Aug. 96.
As Dutchy had reported, to use a 89661-50380 instead of a 89661-50241 was effective to prevent the engine halt problem and improve some other issues.
What I worry about is that the ECU 89661-50380 you used is not a good one or the engine itself has some damage already.
I also suggest you to read posts #179, #390, #393 written by Dutchy. I don't know that your ECU is refurbished or not, a 89661-50380 is now 27 years old and it would be natural to fail if QAS capacitors were not changed yet.
Last edited by Yamae; 01-27-24 at 12:41 AM.
Reason: To add other related posts.
Hello! Thank you so much Mr. @Yamae for the reply! I will be going through all the threads! Meanwhile can you also help with me identifying where to get the latest capacitors that’ll work with the 89661-50380 ECU?
As Dutchy had reported, to use a 89661-50380 instead of a 89661-50241 was effective to prevent the engine halt problem and improve some other issues.
What I worry about is that the ECU 89661-50380 you used is not a good one or the engine itself has some damage already.
I also suggest you to read posts #179, #390, #393 written by Dutchy. I don't know that your ECU is refurbished or not, a 89661-50380 is now 27 years old and it would be natural to fail if QAS capacitors were not changed yet.
Hello! Thank you so much Mr. @Yamae for the reply! I will be going through all the threads! Meanwhile can you also help with me identifying where to get the latest capacitors that’ll work with the 89661-50380 ECU?
Well what can I say, I own a 1995 well maintained LS400 and for the past year my baby has been to so many mechanics dew to rough running but not always and many different issues popping up that i was started thinking maybe its time I give up on it up until I ran into this forum and I figured what do I have to lose at this point. I pulled the ECU and what do you know (a leaked out capacitor and burned out trace from the electrolyte) I am an electronic technician so that was a plus on the trace repair. The capacitors have been ordered and I am waiting to receive them and replace the rest of them and see if this will fix all my issues and help me enjoy my baby for many more years. I'm so happy to find this forum and be a member thank you all for the awesome information. wish me and my baby luck, I will post the results soon...
let's see first of all I want to thank you all so much for this awesome forum.... I did exactly what you all said and ordered the exact capacitors as stated in this forum and went on and replaced all the 6 capacitors and omg all my issues went away including other issues i was having from before woooohoooooooo. thank you thank you and thank you all... I got my baby back thanks to this forum.
let's see first of all I want to thank you all so much for this awesome forum.... I did exactly what you all said and ordered the exact capacitors as stated in this forum and went on and replaced all the 6 capacitors and omg all my issues went away including other issues i was having from before woooohoooooooo. thank you thank you and thank you all... I got my baby back thanks to this forum.
John from Chicago
Thanks for the report. Finding another happy owner, I am as happy as you are.
I figured I would share pics of the repair I did myself. For context, I was experiencing random misfiring and severe engine stuttering. One day codes would read cylinder 3 and 5. The next time would read cylinder 2, 4, 6. Replaced all electrolytic capacitors using Nichicon UBT series caps as well as one Samsung ceramic cap for C110 (thanks to Yamae-san for providing the value of this cap in another thread). Pics will be in before-after order.
Post cap replacement, the car no longer has any misfire codes and the engine runs beautifully BUT the car now has a P0773 and blinking "ECT PWR". I can only assume this fault is a result of the cap replacement job as it was not present prior. I may still attempt to troubleshoot it (any feedback is very much welcomed) but I have continued to drive it as-is as I will most likely retire the car to the scrap yard soon.
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C120 and C141 and C110
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C831 and C121
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C101 and C102
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HumiSeal urethane conformal coating from work
@LScowboyLS Should probably add the 1MZ to the engine list.
One strange thing happened. I just tried to leave a comment on that video. He said in the video that "this is not a common issue with older Toyotas, ECU failure is not common". So I wrote to him calling out that it is 100% failure modes on all 1UZ engines for example, among many many other engines which also have this same defect. All ECU's must be repaired.
This looks interesting but I don't have the dexterity to solder on a PCB. I do live near Berkeley and there's a really good electronics shop that should carry the caps - I also know badcaps also sells capacitors too.
i am also in the east bay whats the name of that electronics store?
Can confirm. I just opened up the ECM on a 94 ES after having increased frequency of transmission error codes P0720, P0500. First once a year, to once a month, now once a drive. It appears to have the same number and value capacitors as the 1995-97 LS400.
Hi. First off, great thread and unreal info, so helpful. Hope someone may be able to give me some direction on my car, well my son's car but I do majority of the work on it (ex-mechanic and auto electrician).
We have a LS400 build date on plate is Sept 1994 and located in Australia. Had the car 18 months now and when we had her she seemed to drive fine, couple of lights flashing such as engine light when first started and TRAC light flashing constantly. She needed some other work and so wasn't run much at all. When we got round to running her again she first started to cut out and not start. It would try but die. Seeing as there wasn't much fuel I guessed it must have run out. Put fuel in, cough and splutter and it went but shuddering etc. so thought dirt in the tank been picked up so cleaned tank out.
Car did not run for months then started to use it but it would misfire, backfire and then over fuel and smoke from the exhaust. I fell across this thread (thank you lord) so pulled the ecu and had a look inside and saw that it had already had capacitors changed. I thought I may as well swap them again BUT didn't read close enough so got some random capacitors from the local Jaycar and swapped whatever they had of the equivalent caps. Put it back together and VROOM... she drove beautifully (still TRAC light on though). Drove it for about 6 km then she died and wouldn't start. Left it a couple of hours and she drove back home and died again just before the driveway.
So, I have a few possibilities and a concern on the actual ECU itself.
1) Cheap caps need replacing with quality ones, Digi-Key have all I need and are in my basket as I speak. 9 caps in total in this ECU.
2) One of the caps has not been replaced previously, still has a Nichicon 15uf 35v PF(M) installed so will swap.
3) One of the caps that has already been replaced is a 0.47uf 63v which I am thinking was mistakenly used instead of a 47uf 63v.
4) Which is a big one, my ECU part number is nothing like any of the ones mentioned (that I can see in any post) it is 89661 - 250TR. Does anyone know if this is correct or if not what this unit is from? I tried Googling but nothing really came up. Car ran well for a while when I swapped the caps before but then broke down (possible cheap or wrong caps) so thinking if I put quality caps in it may run ok but wondering if this may be the TRAC light problem due to incompatibility.
I don't know the ECU P/N 89661-250TR and I can't say any about this.
Looking at photos you provided, I can recognize that the leaked QAS liquid is still on the board and I worry that traces are already damaged. Regarding the TRAC light issue, you need to read the error code first.
Thanks Yamae.
I did get a code for the TRAC but have forgotten what it was now as my attention was on the non start problem at the time.
I have ordered and am waiting for the capacitors from Mouser at the moment, when they arrive I will replace and se what happens then.
Would you agree that the 0.47uf capacitor that was replaced was most likely a mistake for a 47uf?
I am beat about the ecu part number also. I have tried and tried to research that number but nothing shows. really weird.
01-26-24, 04:56 PM
leaky capacitor
