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ECU ECM Detailed Information on location of Computer

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S10 ECM ECU location

So, to try to educate the Hive Mind about where this thing is located, I first offer this video, which has exactly what you need at about the five-minute mark. Because content on the Internet is notorious for disappearing without a trace after a few years, I will also give you a text description. This example is a First Gen '93 S10 which is apparently a stripper "fleet" version just like my 1991, except mine is a single cab, not extended, let alone having jump seats behind the bench. Rubber floor mats, manual everything. The procedure on mine was identical to the '93 in the video.

Here's the YouTube description and link:

"93 S10 4.3 Bad ECM REPLACEMENT!"

Here's my text explanation:

1) DO NOT remove the glove box or any part of the dashboard! All of that is completely unnecessary and just wastes your time.

2) Look UP, UNDER the glove box for a sort of triangular metal bracket with one corner rounded off, attached just to the passenger side of the light that illuminates the passenger footwell (I think). The bracket will have a SINGLE screw that screws in Point Straight Up with a hex head. The video says it's a 7mm, which is perfectly reasonable, but my 7mm socket was too small. I ended up using a 9/32" socket, which a bit sloppy but worked fine. You will see two large rectangular multiconductor plugs with FAT wire bundles just forward of the bracket, plugged UP into the bottom of the ECM. The ECM is NOT in any way attached to the firewall, the kick plate or anything else. It is retained to the bottom of the dash by that single screw.

3) Unplug the two cables, and anything else that's plugged into the ECM assembly. My '91 has a translucent uncolored plastic module attached to the FORWARD face of the ECM. Interestingly, this sub-assembly is not wired into the ECM enclosure in any way. It appears this was just a convenient place to secure it. I think it has to do with the dashboard gauges, etc. It has two connectors on one end, one 9-pin, one 4-pin.

4) Once you pull that one screw, I at least found that the whole assembly easily pulled out straight down.

5) I was pleased and relieved that the size, shape and mounting points of the factory ECM, made for the original 4-cyl. engine, are identical to the recommended "1227747" unit from an early-90s full size pickup.

Good Luck!

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Agree with all of this. I have pulled out several ECM’s from junk S10’s and Blazers while looking for a replacement for my 88 S10 2.5L.
There are several serial numbers of the actual ECM box.
I had to find an exact matching junk truck. It was like Christmas to find the ECM intact.
Once the serial number is confirmed, in my case anyway…I had to remove the wide EPROM cover plate, remove the large EPROM by unsnapping either side.
then I replaced the EPROM with the one from my old ECM.
after plugging it all up…it started up and runs like a champ!! 😁
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