(94 LS400 ECU issues/Running Rough)
09-10-12, 04:52 AM
#61
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<a href="http://tinypic.com?ref=30k6em0" target="_blank"><img src="http://i49.tinypic.com/30k6em0.jpg" border="0" alt="Image and video hosting by TinyPic"></a>
Almost fixed. I'll get the computer back today. I got it repaired for 100 from a ecm repair shop that is small and only for foreign mercedes BMW and Jaguar . But the nice guy agreed to fix my with no warranty because he cannot bench test it.but I had the computer taken apart already and I showed him what I want replaced . Very honest person I'm lucky lol. Got my fingers crosssed ... I should get the ecm back today. I dont if I can handle another catastrophe like this lol I might part ways with her.shes got the gauge cluster eye twitch too... Well kept car tho...
Almost fixed. I'll get the computer back today. I got it repaired for 100 from a ecm repair shop that is small and only for foreign mercedes BMW and Jaguar . But the nice guy agreed to fix my with no warranty because he cannot bench test it.but I had the computer taken apart already and I showed him what I want replaced . Very honest person I'm lucky lol. Got my fingers crosssed ... I should get the ecm back today. I dont if I can handle another catastrophe like this lol I might part ways with her.shes got the gauge cluster eye twitch too... Well kept car tho...
09-10-12, 11:50 AM
#65
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Hey your LS is way too nice to part her away. Someone will steal her away with little knowledge of electronics or have an extra ECU on hand. Hope you get her back on the road. What wheel setup she is on? 18 inch with 1 inch lower? Keep us posted after results. It is a shame on Lexus using cheap capacitors. My 94 Previa with 240K is still running like a champ. No electronics issue unlike high-end 94 LS. Keep in mind, I have an extra ECU in my garage. LOL. As far as your cluster, couple hours of replacing capacitors would make her bright and shine to you again. LOL
09-10-12, 02:14 PM
#67
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Most nowaday LCD and Plasma TV have bad capacitors as well. I did replace my Samsung LCD capacitor on its power supply. Now they even have lawsuit class action against them. Capacitors just have life span. Manufacture want their customers to keep on buying their latest products. Buyer beware.
09-24-12, 04:29 AM
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First....Thank You to Kyuwong, Yamae and cowboy on their detailed pics and diagnosis on these issues. I have a early 95 ls400 and i was on the verge of giving up on it when I came across these article's on the ECU and faulty capacitors. Just to fill you in my car was almost undrivable pouring white smoke and fuel out the exhaust, poor acceleration and an engine miss. Replaced plugs, leads, air flow sensor and all 4 o2 sensors with no results. Last ditch effort I removed the ECU and opened it up and examined all the capacitors with a magnifying glass. I noted a suspect one and jotted down the number on it (cap 831). Next I went down to the electronics store and bought this capacitor for a whole 44 cents. I also bought a $14 25 watt soldering iron. Unsoldered the capacitor and replaced with a new one (it is plus and minus rated). Put it all back together again in the car and started it up. No miss, no smoke, no spitting fuel and when I drove it the acceleration was back. I could not believe the change. If you have these symptoms don't be scared to have a look at the ECU as the fix is fairly simple if you have some soldering skills......Just a final note I was forced to repair my ECU as the part number was different to the part numbers the repair guys quote. I have since found out the ECU was put in Singapore based cars between 10/94 an 01/95 and the only one I found was new and $3100. Part number is ECU 89661-50260
Last edited by AussiLS400; 09-24-12 at 06:19 PM.
09-24-12, 07:20 AM
#69
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09-24-12, 07:49 AM
#70
Lexus Champion
Unsoldered the capacitor and replaced with a new one (it is plus and minus rated). Put it all back together again in the car and started it up. No miss, no smoke, no spitting fuel and when I drove it the acceleration was back. I could not believe the change. If you have these symptoms don't be scared to have a look at the ECU as the fix is fairly simple if you have some soldering skills
09-24-12, 07:58 AM
#71
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Scan both boards of the ECU very carefully with a bright light and magnifying glass. A multimeter would also help to test for a dud capacitor or 2. To remove one hold the cap with some pliers and heat the solder joint underneath. Try not to melt the board. A steady hand is needed and pull the cap slowly off the board. Clear the 2 holes left and place the new cap in paying attention to the pos an neg. On mine the white line was negative. Carefully solder from underneath. Use just enough solder to make the joint. Check joint with a magnifier making sure the solder hasn't run into other joints. Good luck. I only change the faulty ones, the rest could last another 10 years or so. Also there is more chance of a stuff up changing all at once. The job is very fiddly.
Last edited by AussiLS400; 09-24-12 at 08:06 AM.
09-25-12, 03:52 AM
#72
Lexus Champion
Carefully solder from underneath.
Good luck. I only change the faulty ones, the rest could last another 10 years or so. Also there is more chance of a stuff up changing all at once.
In addition, the caps can be bad even if they look fine, always replace ALL of the electrolytic caps (typically around 6 of them, depending on which year your LS400 is)
Last edited by LScowboyLS; 09-25-12 at 03:55 AM.
09-25-12, 06:15 PM
#73
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Cowboy, I didn't realise it was a 3 layer board although when I soldered from the bottom the heat melted the solder that was left on the top of the board. The position of the cap would have prevented me from getting a soldering iron in on the top anyway. At the moment I am just happy to have a car that's running and I suppose I will get around to the others in the future. I,m just coming to grips with this car (95 LS) as its replaced my old 1990 ls400 which was written off by a 6 ton truck last month. I loved that car, it ran like a new car even though it had 470000 on the clock. The new one has only just over 100000 so I was expecting no problems.
09-25-12, 06:40 PM
#74
Lexus Champion
that is the saddest LS400 pic - OMG
don't feel too bad about your soldering job, I just found out I get to re-do my ECM repair as Yamae has identified 3 of the 6 capacitors I replaced as being incorrect ESR type, even though I tried to use the best ones I could find, had to get my LS running in a hurry as well, it wouldn't even shift gears automatically!
by the way, I know it saddens you and was a tragedy, but that pic is awesome - it looks like like a photo contest winner - very cool pic even though it is sad!!
don't feel too bad about your soldering job, I just found out I get to re-do my ECM repair as Yamae has identified 3 of the 6 capacitors I replaced as being incorrect ESR type, even though I tried to use the best ones I could find, had to get my LS running in a hurry as well, it wouldn't even shift gears automatically!
by the way, I know it saddens you and was a tragedy, but that pic is awesome - it looks like like a photo contest winner - very cool pic even though it is sad!!
Last edited by LScowboyLS; 09-25-12 at 06:49 PM.