All my crazy Lexus issues SOLVED!! (ECU-leaking capacitor)
02-18-16, 04:47 PM
#1291
Driver School Candidate
Code 24
On the nissans if the voltage drop is greater than 40 millivolts on the ground wire, after adding the extra ground there would be a definite improvement in driveability. Nissan actually had a part number for a kit to do it. It was basically a wire with a terminal on it and it is no longer available from Nissan. I did not check the voltage drop to ground " negative battery post" on the lexus models I just added the wire to ground and code 24 did not show up anymore. I really don't know why it works it worked on the nissans so I tried it on the Lexus models.
02-22-16, 07:36 AM
#1292
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None of the caps that I had on board was leaking, I just read that even if they look fine it is recommended to replace them.
The reason I replaced only 7 of 9 caps is because I ordered only those listed in first post and the list was missing two 15uF capacitors.
Yesterday I tried to resolder old capacitors to the board and the result is the same - engine doesn't work well. I am sure that I done soldering in a good way. I have electronic education and done many computer main boards repairs before.
So right now I am thinking about two posibilities:
- I have damaged some tiny traces near the soldering holes of caps.
- maybe static discharge has done some damages.
In both cases I have no idea how to check it and fix.
What would be the consequences if I connect the 89661-50351 ECU to my car? I could have it really cheap and if it is safe for engine maybe it is worth trying?
The reason I replaced only 7 of 9 caps is because I ordered only those listed in first post and the list was missing two 15uF capacitors.
Yesterday I tried to resolder old capacitors to the board and the result is the same - engine doesn't work well. I am sure that I done soldering in a good way. I have electronic education and done many computer main boards repairs before.
So right now I am thinking about two posibilities:
- I have damaged some tiny traces near the soldering holes of caps.
- maybe static discharge has done some damages.
In both cases I have no idea how to check it and fix.
What would be the consequences if I connect the 89661-50351 ECU to my car? I could have it really cheap and if it is safe for engine maybe it is worth trying?
02-23-16, 01:50 AM
#1293
02-27-16, 12:39 PM
#1294
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When cold, sometimes my tachometer doesn't work. Could it be leaking capacitors? 
Time will tell but, I'm going to monitor the situation and go from there.
Great info in this thread!
Thank you!
Mike
Time will tell but, I'm going to monitor the situation and go from there.
Great info in this thread!
Thank you!
Mike
02-27-16, 05:43 PM
#1295
Moderator
In order to confirm, you need an oscilloscope to check the signal from the ECU to the tachometer.
But anyway a 94 is old enough for those QAS capacitors begin to fail even in a cold district.
If I were you, I'd simply replace those as a PM. As you see other posts, many people are amazing how their cars run better and consume less fuel after the replacement.
03-02-16, 03:52 PM
#1298
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My new capacitors have arrived. Now, this swap is way beyond my skills. I haven't read this entire thread, so please forgive me if it has been posted but, does anybody know of a repair facility where I can send my ECU that is capable of installing the new capacitors within the US?
Mike
Mike
03-02-16, 09:41 PM
#1299
Moderator
My new capacitors have arrived. Now, this swap is way beyond my skills. I haven't read this entire thread, so please forgive me if it has been posted but, does anybody know of a repair facility where I can send my ECU that is capable of installing the new capacitors within the US?
Mike
Mike
Sorry that I'm half joking you. I basically recommend to DIY but some PC shops are good at replacing capacitors. It would be an idea to find a shop nearby since you already have obtained correct capacitors. If you can't find any locally, search the Net and you may find some company or people that are good at Japanese ECU repairs.
03-05-16, 09:12 AM
#1301
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It appears that one of our forum Vendors offers this service;
http://www.taninautoelectronix.com/V...air-s/1892.htm
I'm still inquiring on a local option but, if that fails, I'm going with Tanin.
Mike
http://www.taninautoelectronix.com/V...air-s/1892.htm
I'm still inquiring on a local option but, if that fails, I'm going with Tanin.
Mike
03-06-16, 05:07 AM
#1302
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Hi!
At first, i don't read the whole tread. A search doesn't give me usefull results.
Does these capacitor issue apply only to the engine ECU?
What about all the other ECUs like TRAC, MPI, doors, Air Suspension etc?
I cant imagine that there more durable capacitors was used,
Will they also fail sooner or later?
If that's the case, i will open all ECUs to replace them all.
Greetings, Stefan
At first, i don't read the whole tread. A search doesn't give me usefull results.
Does these capacitor issue apply only to the engine ECU?
What about all the other ECUs like TRAC, MPI, doors, Air Suspension etc?
I cant imagine that there more durable capacitors was used,
Will they also fail sooner or later?
If that's the case, i will open all ECUs to replace them all.
Greetings, Stefan
03-06-16, 07:40 AM
#1303
Moderator
03-06-16, 09:33 AM
#1304
And it is more of a power train control module than just an engine ECU. The transmission ECU is integral with the engine ecu, they are both in the same box. The other big ecu under the glove box is the ABS.
And it is kind of funny that only one of these boxes would have a capacitor problem, why the bad caps in it only?
And it is kind of funny that only one of these boxes would have a capacitor problem, why the bad caps in it only?
03-06-16, 01:49 PM
#1305
After having my ecu redone by a reputable person I couldn't tell much of a difference. Well the shudder seemed to go away between 3rd and 4th gear but that was it. Now fast forward about 6 months and we has to replace the battery. The old battery was to small for the car they said. So we got the right one and night and day. Friday's replaced the coolant temp sensor and after about 250 miles this weekend it goes even better. I'm not saying it's a fix, just want to share my experience.