Pixhawk 2.4.6 and MaxSonar-EZ0

I have a Quad with pixhawk 2.4.6 and I try to use MaxSonar-EZ0 like this tutorial
http://ardupilot.org/copter/docs/common-rangefinder-maxbotix-analog.html
but after I update pixhawk (using mission planner) for the last version the MaxSonar-EZ0 dont work anymore.

The intent of this project is to implement object avoidance

sonarrange and sonarvoltage = 0