Hey guys,

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| 1 2 3 4 5 6 |
| 7 8 9 10 11 12 |
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Question on what terminals are what. Shortly after I got my '87 IROC, the "Check Engine Soon" light came on. I tried to display the code by jumping terminals 6 and 12 (as I thought this was how I did it on my '85). The Check Engine light blinked twice when I turned the key to "on", and stayed lit. Since, I have learned to display the codes by jumping terminals 5 and 6. What exactly did I do when I grounded terminal 12? This had no nasty side effects to date. Thanks for the help!

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'87 IROC Z28
TPI 305
5-speed
3 1/2" exhaust w/ Flowmaster
Clarion, Kenwood, Eclipse, Polk, MTX, Autotek 1600 watt stereo system
Grant wheel

 

IROC,

Actually, they are not numbered the way you have them labelled. The sequence is as follows:



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Later,
Vader
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"No matter how hard you try you can't stop us now..."

 

IROC,

Also, you probably did no real damage to the ECM by grounding the serial data string terminal "M" (#12 as you have it labelled). The data string is signalled out of the ECM by a digital voltage signal that is pulled up through a 10K resistor, so it is pretty well isolated from the actual IC inverter output to prevent damage from just such an occurrence. Just don't do it any more than you have to.

------------------
Later,
Vader
------------------
"No matter how hard you try you can't stop us now..."

 

Vader,
Thanks for the diagram. That clears up any questions of what terminal is what. Does grounding the Serial Output terminal pose any risk of damaging anything? Pardon my ignorance, but I am new to this! Thanks.

 

Vader,
Only did it the once, and will avoid doing it in the future. Thanks for the help!