00 gmc sierra 570t wont stay runninng

Sounds like two issues. One being a tach issue and the other a passlock 2 issue. Try the ECM under the hood for the tach. Its on the driver fender, white plug (it's labeled), white wire. Use a jumper wire before you make anything permanent. I've had tach signals that have programmed before but for some reason the remote start didn't like the signal. For the Passlock 2, from the PLJX, make sure the blue wire is connected to the Yellow passlock wire and the Black wire is connected to the ORANGE / black passlock ground wire in the vehicle (NOT TO THE CHASSIS).I drink current, eat ohms, and bleed voltage

Starter keeps cranking. I will check the PLJX wiring as noted.