This seems like a sensor problem on the surface, but since the sensor is over 200 bucks, I'm gonna ask the experts.

Symptom: The levelling system appears to keep raising the car higher, even though the load in the trunk has not changed.
I have measured the distance from the wheel-well-edge to the tire on several occasions, and pretty much proved that'* what is happening.
My idea to prove it'* the sensor is to unbolt it from the wheel-well and rotate it to different positions and see if the levelling system reacts differently. (This method seems easier than dismantling the linkage between the sendor and the suspension piece)
Ideas anyone?

Try it and see if you think that it is easier. I've found that leaky shocks will cause the same problem as a bad sensor.

This just gets better and better.
The sensor seems to be working. With it removed from the chassis, I can manually move the actuator-arm and change the run-time of the compressor.

Here'* the weird part:
I let all the air out of the shocks, and when it lowered the car (it was jacked-up), the rear sits at least as high as it was before, so there'* something else going on.

Later, Joe