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Well, i'm going to perform the capacitator replacment this weekend.
1997 112K miles. Original unmolested ECU. Car has intermittent stalling and no restart problems. Also had a slight hesitation all throughout the RPM range. No other issues. I'm working on the car for a relative and he's been battling trying to get it running right for the past year or so. He's spent way too much money on shady mechanics, so I hope this cures it.
I opened up the ECU this evening and everything is pristine in there. Six capacitors and no leakage or any circuit board damage. I was hoping that I'd see maybe a little leakage, just to know I was on the right track. But from what I gather, leakage is not necessarily required in order for there to be a problem.
So just to capture pre-fix issues as I know them, the ECU is throwing codes for mass airflow circuit malfunction, crank position sensor malfunction, catalyst system efficiency below threshold, and intake air circuit malfunction (P0100, P0110, P0335, P0420).
Just waiting on my digi-key order to show up at the front door and then off we go!!!!
Yamae,
I've been monitoring this forum and thread for a few weeks. I own a 2000 Toyota Celica GT-S that has been exhibiting flaky and intermittent symptoms for about a year now. The problems started with intermittently working power windows, then progressed to intermittent ignition or gauge cluster (and other interior functions) operation. it seems to occur more frequently when the car interior is hot from sun exposure. I have inspected the wiring, replaced fuses, unplugged and re-inserted connections in the center console, and checke and re=attached the grounding. all to no avail. It has been difficult to diagnose because of the intermittence, and because the functionality returns after about a minute or two in most cases. I've replaced the ignition switch and the ignition switch relay and the problems persist. Looking at the Celica wiring diagram, all of the functions exhibiting flakiness have the body control module in common. The original post in this thread lists the Celica GT from 1985 to 1998, but does not specifically list the generation that includes the 2000 GT-S. I've poked around the thread, but have not read every single posting to see if this car is mentioned. I have inspected the body control module PCA (found in the center console), and the caps look similar to the ones in this thread, but I see no signs of leakage. I realize that they could be going bad without any visible signs. Are you (or any other readers) aware of any problems with the electrolytic caps in the body control module of this vehicle, or the later geneartion of Celicas? Do you know if the known bad capacitor versions were used in this generation of Celicas?
Hi, GTS.
I'm not familiar to your model and what I only can advise you is that those capacitors are printed PF(M) or PR(M). If yours are so, simply replace those.
I am about to place a Digikey order for caps to replace those in my '94 LS ECU.
First I would like verify the case size information found in the links on page 1 of this thread. Does anybody have a list showing the lead spacing, case diameter, and height for each cap?
I'm not an expert on the subject, but I did do the six caps in my '97 this past weekend. Some of the physical sizes were slightly different between the new and old, but that didn't cause any problems. Also, the leads are flexible and will bend to fit through the holes on the circuit board, so I wouldn't worry about lead spacing.
I'd suggest just order from Digikey (which I did also) via the links on the first page of this thread. I'd also suggest to order one or two extra of each size since they are cheap and if you mess one up during the soldering process, you have some extra.
Things went well on my install. I'm battling multiple gremlins, but it did seem that the cap fix helped smooth out the engine and I'll need to drive it a while to confirm that the odd codes don't come back.
I'd suggest just order from Digikey (which I did also) via the links on the first page of this thread. I'd also suggest to order one or two extra of each size since they are cheap and if you mess one up during the soldering process, you have some extra.
Hey thanks, will do. Actually I already have some of the listed caps from a few flat panel LCD repairs I have done. Apparently the use of cheap caps is not an isolated problem as it is affecting even recent consumer electronics, although in the case of Toyota ECU's it is for a slightly different, specific reason.
It just happens that I ordered very low ESR caps for those repairs for what I would call speculative good measure. I dont think ESR is an issue in a LCD power supply, but I speculate that it cannot hurt. That is to say I cannot fathom a situation where high ESR is actually specified or required. Perhaps an electrical engineer could easily correct me. In any case I have some caps left over that meet the recommendations of Yamae among others.
If you follow the links on the first page of this thread, and combine the work on page 3 (many thanks to LSCowboyLS and 53bel, by the way), you get various case dimensions*** as follows:
*** I am not stating these as fact. I am soliciting confirmation.
Having said that, I am familiar with bending capacitor leads to adjust mismatch in lead pitch, but I prefer not to. Also there is the small issue of case envelope, where a mismatch could be more than a small issue. For example: While you may simply dislike a capacitor possibly touching adjacent components, I think you would absolutely hate a capacitor being so tall you could not safely reassemble the project.
In the absence of timely confirmation I will go ahead on blind faith and order the parts listed in the table above. When I perform the repairs I will label and measure them all and report the results to this forum.
Thanks again to everyone who compiled this useful information. In turn I will contribute what I learn on my project.
EDIT: While I am at it building an unfortunate wall of text, I suppose I should add that I have had two LS400's before this one, both with over 200k miles, and neither had demonstrated any of the issues listed in the thread introduction. My current LS, however, with only 117k on the clock, is acting a little strange. It basically runs great, but not superb. A full throttle launch from a standstill lacks the gusto of my previous cars, it gets below average fuel mileage for the marque, and there is this extremely subtle hesitation off idle and even a little tiny bit of shifting hesitation. Since I picked it up, I have changed the engine oil/filter, air filter, and transmission fluid. I also replaced the plugs, wires, and distributor caps. A "normal" person would never notice these subtle problems, none of which were improved noticeably by the service I performed. I guess I am hoping a little bit that I have the onset of capacitor failure, which is why I am on this little adventure.
Last edited by Diameter; 09-23-15 at 05:30 PM.
Reason: I left some information out the first time
Can somebody help me please just got 1994 ls400 lexus. It drives good for a while then next thing i know the check engine light comes on then at being on less than 5minutes the car cuts off and want start bk, after i let it sit about 10minutes it'll start back then repeat it again, I was told it was the Ecm so I got a new used one and had it programmed hope this does the job and not just a waste of money.
I recently bought a 1997 LS 400, and I've been having issues that fall in line with the capacitor failure, but was working for the most part. I could not get any form of communication with the ECU, techstream just told me it couldnt find the ECU. Then it started to run poorly, seeming lean, so I ordered new caps. While I was waiting, the car began to refuse to start at all, but I've checked everything, it's got new plugs, wire, distributor, fuel filter, injectors are fine, so is the pump, I've swapped the filter, and I've just bypassed the bad fuel resistor. Logically it's only the ECU that caused the issue, and when I opened it it became obvious, it seems like someone has replaced a few of them and failed. One of the capacitors seems to have a lifted pad on the bottom side of the through hole. They ran a wire from the bottom of the lead to the top side, also it seems like a trace may have been damaged and they just ran a wire along that path.
Needless to say I'm going to replace the capacitors, but I'm worried about the lifted pad and the trace. I'll send some pictures to further clarify my point. I was also wondering if you knew how to recode the ECU if this one has to be replaced. Since this is a 97 with an immobilizer it would have to be matched to the ECU, and the locks have to match the immobilizer. I was wondering if I could reflash a used ECU, or possibly remove the ROM chips from my old ECU and swap them into another ECU.
I'm just rather lost, and worried, since my Lexus dealer just said they cant repair it at any cost, because they don't have new ECU's and won't work on a used one.
I have a 2000 ES300 with what I believe may be a similar issue with the ECM (leaky caps). It seems to have codes pop up out of the blue (e.g. – I’ve had P0325 and P0330 codes pop up regularly before and after I replaced the knock sensors and cable to them). It also see the check engine light (solid) and track (flashing) come up the A/C or heat on (does not show a code and resets when engine is turned off). Does anyone have a list of the caps I would need to replace or do I need to pull the ECM, get the current part number and possibly use the list of caps for the 2000 LS400 listed in the earlier post?
I have a 2000 ES300 with what I believe may be a similar issue with the ECM (leaky caps). It seems to have codes pop up out of the blue (e.g. – I’ve had P0325 and P0330 codes pop up regularly before and after I replaced the knock sensors and cable to them). It also see the check engine light (solid) and track (flashing) come up the A/C or heat on (does not show a code and resets when engine is turned off). Does anyone have a list of the caps I would need to replace or do I need to pull the ECM, get the current part number and possibly use the list of caps for the 2000 LS400 listed in the earlier post?
TomES300, I have not done a ES300 to know the capacitors needed. It sure sounds like the capacitors could be your problem though, especially if you live in a hot climate. I would pull your ecu and open it to check the capacitor values and order what you need. The recommended capacitors for the LS400 with the same uf and voltage rating will work fine. I would just temporarily install the ecu back in until the capacitors arrive to save some time if you need the car in the mean time. When I recap an ecu I temporarily install it for about a week to be sure it works ok. I do run a ground wire to it though when I do this. I can not overstate how well the cars I have done run after recapping them. At this point I have done recapping to 11 cars including Nissan, lexus and toyota
Good afternoon 89OLDMAX: Thank you for the response on my situation. To help speed up the process I went ahead and purchased capacitors based on the 2000 LS400 listing, plus some spares (just in case). Today I pulled the ECM (type 89661-0W120) and noticed that the capacitors are not of the type listed in the previous blog entries, but surface mounted “can” low profile types. Please see pictures below (main board, top side, plus a close-up on the 47uF cap). There are the following on the board (I believe these are correct values); 10 μF (2 each, marked 10 / 50V / 9Z4), 100 μF (2 each, marked 100 / 10G / 9G4), 220 μF (1 each, marked 220 / 10G / 915), and 470 μF (1 each, marked 47 / 50G / 9C6). At this point I suppose I need to ask; Do I need to change these caps? I can use the ones I ordered and make them work (although I can look back to the vendor and see if I can find the surface mount equivalents. Can you confirm the capacitance and voltage ratings needed? Appreciate your help with this.
That is a very funny textured work bench you have set that circuit board on the take the pictures. Do you know how easy it is to damage those micro circuits / chips? If the weather is low humidity and you carry that thing around and pick up static electricity, the whole board will be junk.
09-18-15, 06:08 PM
ECU Capacitor Physical Sizes (Lead Spacing, Diameter, etc)
