berrelauto
November 26th, 2014, 07:34 AM
Here's the problem in a nutshell, we have a LS3 with a Speartech harness & E38 ECM with an 09 OS. The trans is a 6L80E that came straight from GM with what we are told is a 13 OS (24264923). The two will not talk to one another. The engine ran on the 09 calibration & a GM tech was not able to flash an 09 OS into the TCM. Putting a 13 OS into the E38 ECM caused the car not to start. Does anyone know what OS should be in both the ECM & TCM for everything to work correctly? Having to buy another ECM and TCM is not a problem just want to know what should be flashed into them so they don't fry another TCM.