[Supras] Non-working '91 ECU

[berniek at technicaldevelop.com]

Dear Rocky:

    Without a schematic diagram the ECU will be impossible to 
troubleshoot.  Many years ago I reverse engineered an early analog 
speed-density system used by Saab, Volvo and the VW Variant.  At that 
time it was made up of discrete components (no microprocessors with the 
added burden of software to figure out).  The MkIII ECUs have two 
boards, one of which appears to be analog, the other appearing totally 
digital. 

    If anyone has an internal schematic of a typical MkIII turbo ECU, it 
would be worth quite a bit to me in $$.  That aside, I'll be happy to 
pay you for shipping for the partially functional one, since there is a 
chance the digital board is OK.  A part of the analog board may be fried 
from the way you describe what happened.  I'll contact you off list with 
my address.

    Thanks.  Let me know if I can help you with anything. 

       Bernie

Rocky Fox had written:

Bernie, I hadn't heard of any way to use a AT ECU with the manual transmission before. I do have a '91T 5spd ECU that has a problem with the o2 circuit, I believe I had shorted the heater circuit for the sensor as that trouble code went away when I replaced the ECU.I 'm not competent enoigh in component level electronics to identify the failed component to repair the unit.