To make a direct PCM connected performance mode switch on LS1 PCM's you need to do the following:
1. Change the Perf Option to "1 Switch"
2. Wire a momentary ground switch to pin J1-71 on the PCM (the blue connector).
Note: Momentary ground means a switch that is grounded when depressed and open circuit when released again. DO NOT use a regular toggle or latching style switch or it won't work. The PCM expects this pin to be grounded only when the switch is pressed to toggle the shift mode.