P1516 engine code

[Sicksty8]

Now this isn't on a swap truck but I was hoping someone would still be able to help me out anyway. So my daily driver 03 silverado 1500 5.3 keeps throwing a P1516 code causing me to lose complete throttle input control. A message comes up in the cluster saying reduced engine power and when I scan it it says throttle actuator control. So I tried replacing it and the same thing still happens. Now I've heard it could be a block ground problem but I haven't checked that yet. Just wondering if anyone has ever had this problem and been able to fix it.