Workbench Flashing

This diagram was originally posted here:

http://www.gmtruckcentral.com/articles/2014/Bench-harness/bench-harness.html

Also note that if a checksum is invalid, the PCM will assume that the flash chip is defective, and will refuse to be reflashed without an extra step - see this YouTube video for details:

https://www.youtube.com/watch?v=oGeMK6LvQck