Can't see how the 2 issues are related. I would expect the brake code to show on the brake system warning light. If that is not then it could be an old stored code. I would try re-setting it and see if it returns. If the ETS light is coming on and off it could be a sign of things to come with a worn...

P0573 tracks to ECM-9400, which is a brake pedal sensor signal too high reading, either intermittent or permanent.

I think this uses the same sensor, check the resistance per this chart