Accuair flashing red lights

[6Dseven]

My ecu was bad, accuair sent me a new one. When i plugged it in I’m getting red lights scrolling down which should indicate low voltage. Battery is charged vehicle running getting 13-14 volts. Accuair has been real good helping me trouble shoot but I can’t figure it out. Was working fine before just had a draw and it was constantly trying to air up RR was why I sent my ecu in and they confirmed that it was bad. Nothing has changed on the truck other than switching the ecu out. I have checked grounds and power. Any ideas? Thanks a lot