Obd2 port
Ok the problem I'm having is with the obd2 port. When I go to try and write with HPTuners it fails with error: mode 1 erased failed. emailed back and forth with tech support at HPTuners. They said that it was a battery or wiring/ port problem. Well I bought a charger and did a 4amp medium charge then switched it to 2amp trickle charge over night. Tried to load the file again this morning and the same error came up. Another issue after I get the error is having to read the entire vcm in order to start my vehicle again. Has any one else had this issue? Does that port need to be grounded? The wire seemed fine. I really dont understand how my tuner before I got HPTuners was able to write my file but im not able to. Tech support also suggested that maybe I need to do a standalone harness or bench tune, really don't want to have to take the ECM out every time I need to tune my truck. Sorry for the long post and thanks for your help in advance.
Oh yeah I'm able to scan and delete dtc codes.
2015 Yukon SLT
2000 RCSB 6.0/4l80e
1967 Chevy II 5.3 w/ 76mm snail