2011 c1391

So about a week ago, my wife's car popped up a c1391 code and I'm looking to diagnose and repair the issue myself as I'm aware that the actuator and accumulator assemblies respectively are expensive parts and probably more expensive to have a dealer/shop fix.

For starters, (what I believe to be) the accumulator assembly (black and silver cylinders attached to a manifold) vibrates about every 3-5 seconds. The noise is audible from the driver's seat and the vibration causing it is visible with the hood open. I haven't checked the fluid level and whether or not it changes significantly when the car is running but i will when i get home. There are multiple lights on in the heads-up display, all related to the brake system (abs, trac. control, etc.) and the car has lost regenerative braking and now brakes like my old chevy pickup.

Furthermore, I'm assuming that this is an accumulator/master cylinder issue and that's what I'll be replacing. Will I need any special equipment other than hand tools and brake bleeding equipment? I've seen techstream thrown around on some threads here but I'm not familiar with it or what I would need to run it (i'm not too computer savvy but i'm not totally illiterate).

Any assistance will help. Thanks!