I looked that up and seems to be what you have. We don't have many pecan trees this far north.but I do have 1 in my yard. I'm always watching for pests and diseases on it. The only bug I found was the pecan spittlebug and from what I read they weren't really a concernI think I found it... I was thinking galls and googled brown galls on pecan leaves and this came up:
Pecan Phylloxera
Is that what they are?