P1671 MIL Control Circuit Malfunction - With Automatic Transmission

sounds like there is a problem with your mil light circuit I would start testing some connections if the bulb is working if not then i am guessing it is a burnt out bulb

also check fuse 12 in the under hood fuse panel as it relates to that circuit

This can also be caused by a bad pcm so if you have changed it recently or have a spare to swap and try than you could do that.