ICP Navistar Sensor 7.3

Hello everyone, I'm looking for help. I have a F450 Navistar 7.3 mod. 2003 and scanning marks as failure P1212 ICP Voltage Not AT EXPREED SENSOR. When he grabs a little temperature he fails a lot and can't even vacuum. (No load). I already changed this sensor and follow the same failure. Thank you very much for your help.