ob 2 po740 with po455 repaired with no fault code repeat but still po740

Customer Concern: Check engine light is on. Trouble code P0740. No RPM drop At lock-up is set in the Powertrain Control Module (PCM). Tests/Procedures: 1. Check the fluid condition. If dirty or discolored, or if there is clutch material in the pan, the torque converter has likely failed. Rebuild or replace the transmission as the debris will be in the whole transmission, be sure to flush or replace the cooler as well. 2. Perform the Torque Converter Clutch (TCC) test using a compatible scan tool. The engine should stall when running this test. If it does not, then it is likely a mechanical problem in the transmission. Potential Causes: Transmission Mechanical Problem Diagnostic Codes: P0740