Air Bag blockage

Hi, I’ve got air bags installed with the Airlift Wireless system. About a month ago my bags remote started reading “BLOC” everything the compressor engaged, and the bags are gradually losing PSI.

I tried tracing the lines out looking for any leaks, but everything looks good. I called the shop that installed it thinking I’d bring it in, but they told me it was probably just some condensation in the lines that had frozen (we’ve had a cold snap). He said to do 2 things:

1. Find the black box downstream of the air compressor and bleed the valve at the bottom

2. If that doesn’t work, disconnect the hoses from the bags, and engage the compressor, hopefully blowing the condensation out

Was wondering if anybody’d Had experience with this? I found the black box and what I THINK is the valve (it’s a little nipple at the bottom of a cylinder right next to the box.

And how exactly do the hoses detach from the bags? I don’t want to start prying on them and make matters worse by breaking an o ring or something.

Thanks