RAV4 P2118 code

[Ivan cruz]

hey guys my name is Ivan and I need your guys help my grandpa had a 2004 RAV4 that's has a p2118 code also known as Throttle Actuator Control Motor Current Range/Performance and we have replaced the throttle body still having the same problem we have checked the fuse and it is not blow and have even replaced the throttle position sensor but nothing a thing we have noticed is that the connection for the throttle body has low voltage and even the position sensor has low voltage but when you press on the peddle it only goes to 3 thousand rpm 

Another thing is that cylinder 1 and 4 aren't firing at ruff idle and only work when you press the pedal.