OK for this particular year here is what the pcm wants to see... This is STRAIGHT off of GMs service homepage, Id love to hear how THIS is not correct info.The Torque Converter Clutch (TCC) should not apply unless the transmission has reached a minimum TRANS FLUID temperature of 8°C (46°F) and ECT temperature of 50°C (122°F). Note when the TCC applies. This should occur in Fourth gear