Chargo load regulation or similar

Hi there, new in here so sorry for stupid questions.

I have a Gen. 2 Prius 08, and after a technical control I got some errors to fix.
The problem is I don't know the name of the part that is broken.
It should have something to do with load regulation, to make rear brakes a bit stronger when car is heavy loaded.
When I look under the car at rear left side I can see a small metallic rod that is rusted in two parts.
I was thinking it was some kind of fixture for anything, but could this be the part regarding this load regulation?
Was not aware about any load regulation on this car, and can't find anything when I search online for it.

So any good tip to what this could be?

 

and thx for answer.
Not the loading capasity I was thinking about.
Just looked under the car again, and it should be a short and thin metal rod between the undercarriage and bodywork. The top part is fitted to a lever arm from a sensor box connected to some cables. I guess it read out how heavy the car is loaded.
I need the name or partnumber for that small metal rod.

 

Yes, that was the error pointed out at the test, Level adjustment of headlight not working. (not a code, just told by the guy testing the car)
But at my car it is normal H4 halogen bulbs in the headlights, and a manual height adjustment knob at the dashboard used to turn lights down if heavy loaded in the rear.
So not shure if this sensor is used for anything at my car?

I guess it is this part from what it looks like under the car:


Called PRIUS HEIGHT CONTROL SENSOR REAR LH or similar.

Only the part connecting the sensor to the rear suspension is broken, but it seems that you need to replace the whole sensor.
And it is a bit expensive, so if it is not used in my car I don't see the point replacing it.....