How to test rear ride height sensor

Brought in the car to the dealer ship to have a electronic control module calibrated to my vehicle. Installed but the computer would not communicate with the level sensors came back with error codes for each of the four level sensors. I have tested the sensors power pin in the three pin connector going to the sensors. Three had five volts At the connector the other 0.00 volts traced the wire back to the control module to find no issues with the wire. Tested the wire for five volts directly at the 47 pin harness connected to the electronic control module and still 0.00 volts. I am now getting concerned that the electronic control module may have an internal malfunction that was not caught by the dealership. They had mentioned that maybe one of the sensors has failed causing it not to send the five volts down the wire to the height level sensor. Is there any way to test the height level sensor to see if it needs to be replaced?
Thanks