Ive been looking a little closer at the high and low res signals. Later I will post the ins&outs but I have run into a little snag. There is yet another unidentified part and I could sure use some help. Way back when I had a bunch of contacts in LSI logic / Symbios but with M&A activity I have lost touch. There are a couple of Symbios parts on my board. One is the part that drives the injector transistors. It's the other one that needs investigation. It is probably a small gate array I expect. Here are some details...
Part is marked:
609-3700521
CP08978
144436
9638N
SYMBIOS LOGIC
726
I will attach a 90% hookup wire list for the part. Only 90% because it is SO hard to trace all the copper.
What would help is to know which PCMs have the part. For example if it is on all boards with Opti-spark that is a tell. Also interested if it is used anywhere else (I expect not)
At first I considered if it could be a phase lock loop. This is still one possibility, but I don't think an engine controller needs that kind of resolution. I now believe it is a counter timer chip. It has interconnections with the mysterious 3rd processor TPU chip.
I have not yet connected my optispark simulator but once done I will set the scope on this part and see what sense I can make of it. Some control of this part is handled by the port replacement chip (66285). It would also be nice if anyone knows the pinout for the PRU to send that along.
-Tom
I am adding a picture of the board (red/black connectors...eside) with the component highlighted
DIG1_RB_CS.jpg
Reply With Quote
Bookmarks