2018 Ram parking sensors
 

I put in an aftermarket stereo (for the Apple CarPlay), then had to add some other contraption (PAC RP4-CH21 - $115) to keep the truck computer happy. Everything works except for the tone for the parking sensors. There is another contraption I could buy (PAC ControlPRO 5 - $150) to make the sensor tone work again. Anybody know of a workaround before I cough up more money than the price of the stereo? TIA.