Mercruiser shift ANT sensor fault

[02809Bristol]

i have 2004 350 mag Mpi w/ alpha gen 2 outdrive
im getting a audible alarm just over 3500rpm. Fault is SHIFT ANT SENSOR ????
it doesn’t go into guardian mode , just annoying beep . Any ideas ? Bad shift sensor, if so which one. I read somewhere ANT means anticipation sensor??

 

[alldodge]

Its the shift switch on the shift plate, it needs adjusting or replacing
The in gear switch is telling the ECM that the boat is not in gear, and beeps starts above 3500