Flyin t/a

I've been having a weird problem lately, when i start my car and took off smootly no problems however if i give it a nice bit of gas so it jerks taking off my low trac light, abs inop, and the parking brake light all come on, the low trac goes off but the abs inop and the parking brake light remain on. I checked the all the connections for the abs sensors and abs unit and they're all good. All the fuses are also good, i noticed that if i pull the abs relay out the same two lights come on on the dash, I tried switching the the blower relay with the abs one and the same problem still occurred, anybody have any ideas? I have a spare abs unit that i could swap in but i'm guessing the problem lies somewhere else possibly in the wiring.

Also is there anything special that i need to know about swapping out the abs unit for my other one, do i just put the new one in and bleed the brakes like i normally would or is there a different process?