92 PA leveler?

I have a 92 PA, and sometimes the rear air lift shocks don't always pump up when I get more people in the car.
I am thinking it could be the leveler sensor?
Where is it located?

I assume, sometimes it works and sometimes it does not, is that correct? The sensor is located on the right side rear mounted above the rear lower control arm. It has a lever that connects it to the control arm.

THANK YOU! AND Yes it does not always work.