I am trying to read a 2002 Suburban 5.3L PCM for a swap. I get an Invalid Checksum message when trying to read it. Using a bench harness and 13.5V supply. Both high and low speed - same thing.
I reprogrammed the PCM successfully with GM SPS and a MDI through Techline Connect but I am still getting the Invalid Checksum message when trying to read with HPT . I tried both the Reprogram and the Replace and reprogram options without any difference.
is the PCM toast or is there anything else I can try?