That's good then. If all the sensors and offsets are reading correctly you have a hardware issue.

Have you checked the proportioning valve and lines at the big air tank under the truck for leaks? There is front/rear distribution on that solenoid and a gasket material between.

This tank and the solenoid (I have 2 because I was chasing my issue :():

https://i.postimg.cc/xTr730QD/Air-Su...n-Repair-1.jpg

I did take the bottom panel off and soaped all fittings on the tank and proportioning valve no leaks. When i did the ista test it checked all functions of the valve, tank, compressor, sensors etc. They where working.

I am not sure if there is an exhaust valve on the pump itself. my next step is to get at the pump and verify that nothing is leaking in there. pump does get up to 15.5 bar so it is working properly. No water leaks in spare tire compartment.

It is so intermittent that is is hard to locate the problem. Maybe a sticking solenoid. This is why i am wondering if the proportioning valve is serviceable.

I disassembled one of mine. It is "serviceable." I don't your find individualparts (I couldn't when I tried), but it was easy enough to take apart and reassemble so a fix could probably be improvised.

I went through this same song and dance for a month or so. :dunno: :rolleyes:

When you took you valve apart could you see any evidence of sticking or leaks?

I did not. And since I had the same results with both valves and tanks I moved on in my diagnosis and ruled out those components as the problem. :dunno:

I do miss my air suspension's functionality, but I do not miss the headaches. At all.

:iagree: There are many other things to worry about on this car. I would like to drop the air suspension off my list.

Suspension is fixed!! Seems that it was a leaking airbag after all. The reason it was intermittent was the height of the car would put the airbag roll in a position that it would leak. Slow leak just at the fold. When not in position it would hold air.
It was being particularly bad one day so I rechecked the bag with soap and water and found it.
I replaced both air struts and now the car is good. Odd thing is this is the second time the bags had been replaced . Once under warranty at 52000 miles and now at 82000 miles.

I am just ecstatic that it is fixed �� !