Originally Posted by
abc
I don't think this is the same but I will mention it just in case is sparks something: I suspect HPT is only capable of locking the converter if specific variables are met. For example: I tried to lock the converter (on a PO1 PCM) that was calibrated to only lock up in 4th. I was in 3rd at a low throttle angle and pressed the TCC lock button in HPT and the convertor would not lock. I did not test this theory any further and dismissed it at the time as I knew the TCC was functioning correctly with the current calibration to lock up in 4th above 50 mph and below 40 percent throttle angle.
I know this is a GEN 4 forum but another piece to note: In my PO1's, the Shift Lock Enable does nothing whether it is enabled or not. I read on this site that some of the PCM's got the button in HPT but there is no function to it.