Engine brakes high level not working

[Yady]

I recently bought a 2016 Kenworth T680 that was de-mandated and I'm wondering how I can check it to make sure that it's correct. The issue I'm having is that the third level (high) of the engine brakes isn't working.

[Bengy88]

Does it still have vgt? If not then there’s your issue. Always assume a demandate is bad unless you’ve had it verified by someone trustworthy. If it is vgt deleted then it’s bad even if it’s good…. Read that twice.