LML Exhaust Brake Problem - I think

[2013 Silverado 3500]

I have a 2013 3500.
For the first 4500 miles, the exhaust brake worked good, now it barely works.

I had a friend data log it and we found when the commanded position is 0% the actual goes down to about 22%
and when it is commanded to 100% the actual goes up to about 84%.

Since we don't have a baseline, what can you guys offer for data?
Should we be seeing actual % at or near 0 and 100? I would think so.

Data log 0 to 100 resize.pdf

Thanks in advance, J.

[2013 Silverado 3500]

Click on "Data log 0 to 100 resize.pdf" to see chart.

[2013 Silverado 3500]

Any body ?

[2013 Silverado 3500]