Traction Control & ABS light on
 

Recently purchased a Scion FRS from someone, the owner did an wiring harness swap he claimed, nothing seems to be wrong with the car but there is a traction control and ABS light that turns on after I drive a few hundred meters. Doesn't seem to be affecting anything tho. I scanned the car and these codes popped up: B1407, U0155, and U1201. theres also a TPS light on but I doubt that has anything to do with it.

It doesn't really affect how the car drives but it irks me that I can't turn on Track Mode or whatever.

Will this be an easy fix? like buying a few sensors or plugging some stuff in or would I need to take it to a shop?

Couple things to check:
All grounds
Condition of battery