Originally Posted by
2xLS1
I've seen probably over 100 T43 TCMS right out of the AC Delco box. In all those I think only 1 was actually blank and showed no segments. I program them for a few transmission shops. They typically don't have VIN #s in them but they have 4 valid segments. Usually not correct for the vehicle they are going into but can usually be programmed with a Write Entire if you read the original TCM first. I usually do them with a bench harness and Tunercat but I've done a few with HP Tuners too. The trick is reading the original before it is turned in for a core. And Tunercat programmed the one that was actually blank with it's force full program mode which is the same as HPT write entire.