I went to read a spare ECM and it failed and said "invalid checksum", what does this mean? It read my other ECM just fine.
UPDATE: I hooked my OBD2 reader to the computer and found no codes, but did find the Calibration ID as 12208322 and under that this number 09357827. Does this mean that this computer has been calibrated/modified and locked?
I just started tuning and can anything be done, other than a complete flash, to change this, or is this computer trash?
