Rapid CEL flash after 7427 swap

[Casey]

For those of you who didn't see my first thread here is a quick recap; I wanted to swap my '91 Suburban from the 7060 to the 7427 because my transmission needed a rebuild, and I wanted to run the '93+ force motor so that when I executed my planned 8.1 swap the transmission wouldn't need to be messed with.

Since then I have repinned my harness using Daveo91's excellent guide and received a lot of help from dave w. The transmission is installed and all of the connectors are in. When I turn the key to the "on" position, the check engine light rapid blinks. The first thing we tried was a refurbished PCM, then dave sent me a G1/chip to see if it was the MEMCAL. Every combination between the PCMs, G1, and MEMCAL yields the same result.

I checked my wiring for the 3rd time today, and am 99% sure I have it correct. Should I try a 3rd PCM? Is there another possibility I'm missing? I ended up buying a '94 454 since the guy with the 8.1 was taking so long, so I'm fully invested in making this 7427 setup work. Any help or suggestions are greatly appreciated!

[In-Tech]

Rapid CEL is generally a bad checksum.
If you want to post your .bin file I, or someone, will check it for you.

[dave w]

File from http://www.gearhead-efi.com/Fuel-Inj...Information-31 . . . BNKM-$31-5.7L-4L80E.bin

[In-Tech]

Interesting, at a glance the file looks fine but someone has been in it and didn't fix the checksum or the file is corrupt. I don't have a clean read of that .bin to compare, sorry.

Here is that file with the CS corrected which will stop the rapid CEL and limp mode.

[Casey]

Thanks Carl, I got a chip installed with the .bin you corrected the checksum on and the blink is gone!