LScowboyLS

No


yes he is!


Not if it is your original ECU you are working on, but say if your ECU was toast from capacitor corrosion and you had to get another 98 GS300 ECU from a junkyard or ebay and then replaced the caps in that one (as you absolutely should) then you would need to have it reflashed by the dealership or some locksmiths can do it as well (like the one in the video) - so YES, you would, and sometimes that service is not cheap, depending on how competitive the market is where you live. Somewhere like Atlanta or South Florida should be much cheaper to have this done as opposed to West Haystack, North Dakota, where you will likely pay dearly!

sayow

Finally pulled my ECU (93 LS) and upon taking a look, none of the capacitors seems in any way damaged.

I know that does not necessarily mean anything so I am sending it off anyway to have them replaced... but was hoping they were trashed for some confirmation. Then again you guys take a look, maybe I missed something!

LScowboyLS

well first of all, bad caps are only sometimes obvious, sometimes they have gone bad but the corrosive leaking has not yet begun. - when my 96 started having issues, I opened it and it looked just like this, so i sealed it up and went on looking for the problem elsewhere - 5 months later, and tired of having the car only get worse and worse, and unable to find the source of the problem, it was starting to become un-drivable, so I forced myself to pull the ECU and look again, and by that time, the perfect ECU had massive corrosive leakage damage and was nearly a terminal case. - So when it starts, the deterioration is amazingly fast!

also, your pics are such that we can only see up under just a couple of the caps, sometimes the leakage is a bit hard to spot in the early stages, especially from a top view

but be thankful that you don't have the severe corrosion that some people opened their ECU to find, many of them had to start over and find one in this shape, and then have it recapped - and also be thankful that your ECU hasn't been rebuilt, because they are usually only able to withstand a single rebuilding, so if you had opened it up to find it had been worked on previously, then you would likely need to find a "virgin" and then have it done.

LS400 owners would be really proactive and smart to do their ECU's before the damage occurs, rather than afterwards and have to replace the ECU and have it fixed. Yamae has been preaching this for years, but no one paid him much attention until lately! - he wasn't as loud as I have been, so people didn't pay him any mind long ago.

The cool part is, many folks who replace their capacitors additionally are rewarded with better mileage and more low-end power. This makes sense, since the ECU is now healthy again and can make accurate fuel trim and timing decisions.

Fantastica

I need your expertise. I have a 1998 Supra NA that I've been chasing issues on for a few years. A few weeks ago I ran into this article, and some things clicked. So, I matched your suggested caps with what I found inside and sent it into a local ECU repair company.

Today I got a call from their tech saying that a few of the caps don't match the specs, and that he has the ones that are needed. I told him that the caps I sent were recommded. The only issue, when i asked, was the voltage. My wife was an aviation electrician who did 2M soldering, so I inquired with her what adverse effects a higher voltage cap might have on the ECU.

My question to you is, will the caps recommended in post #1 cause any shorts, or have any other effects since the voltage is higher than spec?

LScowboyLS

No, higher voltage is fine. In some cases it's even better than the original spec, as there is more room for error, much like using a larger wire when installing a car stereo is always fine, but too small of a wire can get you in trouble!

I already have never seen an ECU repair company that knew what they were doing, and if they really said something about the voltages being higher than original, then you definitely need a different company working on it! (someone with an electrical engineer on staff )

LScowboyLS

PS - do NOT allow any caps to be supplied by the repair company, it seems that no company I have ever seen the work of, understand the very rare caps that are required, which are long life, low-ESR, high ripple rejection, high temperature premium Japanese capacitors, only made by 4 companies, and also must be traceable to the manufacturer's authorized dealer, as counterfeit caps are rampant and a huge problem.

Please do not allow any caps that are not from the links in post #1 of this thread to be used, or the repair will not work correctly. All capacitors that will work are listed, and if a different cap is recommended, please submit it here so that Yamae or I can approve it.

nthach

I've asked this before, but for those of us who aren't confident in our soldering skills, who can replace the capacitors?

LScowboyLS

You can replace the capacitors! (after lots and lots of practice on old junk computer motherboards!)

or else seek out a technician (usually a female, believe it or not) who solders fine electronics for a living at your local high tech electronics manufacturing plant - but make sure YOU supply the capacitors!

Fantastica

They were local, and offered a lifetime warranty on their work. I did not let them substitute, though. Also, all parts were ordered from digi-key. Thanks for the quick reply Cowboy, and thank you and Yamae for the write up and constant feedback over the years. Not enough people like you two on the forums.

Twista4004

^^^^^^^

+1

Michael

I just replaced mine (thanks to LScowboy). I have 93 LS also. None appeared to be damaged on mine. However, I was going to replace all anyways for precautionary measure. In the process of replacing, I could not tell for sure, but I found one that appears to be just starting to leak.

Replacing caps were not hard as none of caps were surface mount type. With a little bit of practice, I think anyone can do this.

After the replacement, I am noticing few changes. I did not have any major problems with engine running or erratic trans problems but had sticking speedo/tech needle and had CEL & TRAC-OFF light with code 25 & 26, that just did not go away. Those problems seem to be gone. I will have to keep monitoring as they may reappear but it seems to be gone for now.

These caps will leak eventually as it has shown in this thread. If you have put an effort to remove the ECU, why don't you replace all 8 of them. It only cost me $6, including shipping cost.

ayanteeque

I am comfortable removing the ECU but don't think I can do the repairs. Is there a good company that I can send it to that can repair it.

Symptoms:
Won't turn over
Had it diagnosed to be the ECU not sending a signal out.

Please HELP!!

LScowboyLS

when you say won't turn over, do you mean won't start up?

"turn over" means cranking - like the sound a car makes when you crank it before it catches and starts

if the car will not crank (as opposed to start up) then the problem is not the ECU

qha_vn

i bought a spare ECU and plugged that in. runs fine so far (a little better). ordered required caps. will soldered them in shortly. thanks for sharing.

i tried to open the ECU boards but didnt know how. scare of damaging it. pls show how if you can. ls400 1990.

LScowboyLS

you have to remove the screws in the board and any screws on the sides, and then the board should come free with a very gentle pry on the corners with a plastic pry tool

do not force it - keep looking for additional screws if it does not come free easily with gentle slight pry