My Silverado shows a code ECM wasn’t programmed right can I flash ECM with VXDIAG GM diagnostic tool?
Look at these images for more details:
vxdiagshop.com engineer replied:
for ECM Reflash, need to perform with SPS programming online. You need SPS subscription from ACDelco TDS website.
Read related guide: Chevy ECM Programming with VXdiag GM GDS2 and SPS
Hope it helps!