dicer

Just wondering how the outfits that repair the ECU's and other black boxes get the repair information that they have to have to accomplish the task? I'm sure they do more than just change out the electrolitic's.

Yamae

I was wondering who can answer your question.
So far none of us.

RA40

iTrader: (6)

Probably in the same way Yamae has taught us to read the ripple results with a multimeter. In the case of the more EE minded they have their oscilloscope to analyze the various signals being set to-from the ECU's.

For all we know with these Lexus ECU's they read Cowboy's thread and have now become well versed.

dicer

I had a ford one fixed one time few years ago. It had a destroyed resister couldn't read the color code from water damage. So Schematics and service info must exist for some people.

billydpowe

iTrader: (1)

well, why not go to the people who fixed your Ford and ask them?? seems reasonable to me, and then you can answer questions instead of just asking them... that would be a welcome chore..

dicer

Because I don't know who did it. The local auto parts store sent it there, like 2000 miles from here.
They would just say sorry that's our little secret, any way .

billydpowe

iTrader: (1)

yep, I sure agree with you on that .. like a dead end street..
you might try this?? all that stuff is over my 80 year old brain, in my day you just followed a wire till you found a bad spot and fixed it ... that is why we were called mechanics, now days you guys are technicians... your thoughts are far above ours..

billydpowe

iTrader: (1)

in another thread PD said: the very first link at the top of the LS forum titled "Service Manuals" is what you want

and its free

Yamae

There is no detailed information regarding the ECU for our LS400. Denso does not open it at all.

What you need to do is to analyze the board and in/out signals all by yourself. You need to use your brain, an oscilloscope, a logic analyzer, a multimeter, a frequency counter, a spectrum analyzer, simulators, electronics loads and others in addition to the service manual. Sometimes a soft X-ray machine is needed to know traces and semiconductors.

Due to the strong requests by local shop owners, I have analyzed some of the circuits just for my curiosity. As long as I fix different ECUs as my hobby, electrolytic capacitors, transistors, resistors and ICs are common components that failed. It is not the often case but chip ceramic capacitors are sometimes internally short circuited.