Fast charge with usb-pd, only 5V applied？

[MervynYelt]

I bought a pd charger which supports 5v/2.4a, 9v/2a, 12v/1.5a and a cable supports 3a.

But only 5v/2.4a applied. Why it can't get a higher voltage?

[Strampke]

Maybe this post

from @Jonas gives you the answer.