Any Mechanics Here Today

[oohryry]

I know this isn't the forum to be asking this, but I thought I'd give it a shot anyhow. My 91 Ac Legend has been sitting for months because the ECU burned out. I got a replacement unit last week. Question, can I just replace the unit, or do I need to take it back to the shop and have them replace it and put it on a machine to test and see why the first one burned out.

Also, what is the cost of a code reader, where can I purchase one and are they relatively easy to use? How do you know what the number code stands for after it is read? Thanks.

[ArmyofOne]

I know this isn't the forum to be asking this, but I thought I'd give it a shot anyhow. My 91 Ac Legend has been sitting for months because the ECU burned out. I got a replacement unit last week. Question, can I just replace the unit, or do I need to take it back to the shop and have them replace it and put it on a machine to test and see why the first one burned out.

Also, what is the cost of a code reader, where can I purchase one and are they relatively easy to use? How do you know what the number code stands for after it is read? Thanks.

you can purchase a code reader at autozone, for relatively cheap. some range into the ~$250 range, but you can get them for as little as $100.

Its a fairly common problem on the Gen II Legends...just throw it in yourself. that happens to computers when they get old, they just burn out.

oh, and watch those headgaskets

[oohryry]

I know this isn't the forum to be asking this, but I thought I'd give it a shot anyhow. My 91 Ac Legend has been sitting for months because the ECU burned out. I got a replacement unit last week. Question, can I just replace the unit, or do I need to take it back to the shop and have them replace it and put it on a machine to test and see why the first one burned out.

Also, what is the cost of a code reader, where can I purchase one and are they relatively easy to use? How do you know what the number code stands for after it is read? Thanks.

you can purchase a code reader at autozone, for relatively cheap. some range into the ~$250 range, but you can get them for as little as $100.

Its a fairly common problem on the Gen II Legends...just throw it in yourself. that happens to computers when they get old, they just burn out.

oh, and watch those headgaskets

Wow, thanks ArmyofOne. I'll put it in and purchase a new battery tomorrow. I wasn't sure if it was something that caused it to burn out or if the shop that replaced the ignition switch did something wrong because that's when it stopped working. Thanks again. I heard about those headgaskets. Mine is probably having problems, I just don't know it yet most likely.

[LScott400]

I wasn't sure if it was something that caused it to burn out or if the shop that replaced the ignition switch did something wrong because that's when it stopped working.

:o

I don't know how much you have invested in this new ECU, but that sounds like Russian roulette plugging it into an electrical system that may have ruined the previous one. I don't mean to sound alarmist and I hope it's a simple case of plug'n'play, but you didn't include that last little bit in your initial question.

I'm curious to know what specific failure the old ECU exhibited.

A common problem on these cars for no-start is the Main Relay. My daughter's '89 left her stuck at Wal-Mart. It wouldn't do a thing when you turned the key. I dropped the relay, popped the cover, touched up the solder joints and it was good to go.

[oohryry]

I wasn't sure if it was something that caused it to burn out or if the shop that replaced the ignition switch did something wrong because that's when it stopped working.

:o

I don't know how much you have invested in this new ECU, but that sounds like Russian roulette plugging it into an electrical system that may have ruined the previous one. I don't mean to sound alarmist and I hope it's a simple case of plug'n'play, but you didn't include that last little bit in your initial question.

I'm curious to know what specific failure the old ECU exhibited.

A common problem on these cars for no-start is the Main Relay. My daughter's '89 left her stuck at Wal-Mart. It wouldn't do a thing when you turned the key. I dropped the relay, popped the cover, touched up the solder joints and it was good to go.

Thanks, I haven't put it in yet. I paid 80 dollars for it used so I wouldn't be upset if it blew out again. I just wanted some insight on the matter of ECU's. Do they actually go bad or does something HAVE to cause it to go bad. If they caused it hooking up the ignition switch and the wiring I would suppose that it would work now that the job is done. But of course I'm not sure so I bought a used one to go cheap first before I find out whether or not to let her go. Even though my Lexus is my sweetheart, I still got feelings for my mistress 91 Legend, cause she rode problem free past the time she was paid for. I got much love for her.

[LScott400]

Do they actually go bad or does something HAVE to cause it to go bad.

Both are possible. The following is from the webpage of an ECM rebuilder. It applies to many Japanese makes from this time period.

Mitsubishi/Honda ECM failures -- Fact or fiction:

The fact is, the Mitsubishi and Honda models of ECMs and TCUs manufactured within the years of 1989-1994 utilize certain electrolytic capacitors that after a certain number of hours or mileage, begin a systematic breakdown. These capacitors eventually break their seal and leak the electrolyte which is a corrosive substance. This corrosive substance actually destroys the area of the mother board computer chip and any adjacent components will be adversely affected. So the longer one waits to repair the unit, the lesser a chance there is of reparability. Most units are repairable unless there is damage to a part that is not made available to us. Presently, their are specific components that are damaged occasionally that we can not purchase. We are the first company to specialize in this field and we have the best technicians in the business. The hardest component to acquire is the processor chips. The processor chips are imbedded chips or IC chips that contain vital information which is copy written and is likely not to be able to access. In most cases when the IC chip or chips are damaged, they will experience a heat to the imbedded chip which will damage the chip and often a heated IC will have a variance on the smooth surface of the chip from the heat. The variance may be in the form of a bubble or rise or in some cases a hole or crack is blown though. In these cases, we can possibly change the IC chip if another donor computer is available. This will be the only time the repair cost will be affected due to the fact that often we must purchase the unit for the specific IC application. When this occurs, you will be informed of the change in the price quote and upon permission, we will change the IC chip processor for the additional cost. The warranty will not be affected.

[SOMEONE ELSE'S GOT MY NAME]

Also, what is the cost of a code reader, where can I purchase one and are they relatively easy to use? How do you know what the number code stands for after it is read? Thanks.

you can purchase a code reader at autozone, for relatively cheap. some range into the ~$250 range, but you can get them for as little as $100.

Its a fairly common problem on the Gen II Legends....

Must be a different code tool being refered to. Upon inquirey, the dealer / parts dude quited me $1,500 -ish. Maybe it's just for the newer cars? This tool that I'm refering to reads codes, and also programs smart keys.