200 bucik regal needs help any gm diagnostic people help?

i have a 200 bucik regal ls 3800 it started acting funny would turn the key into aux and everything would flash if i tried to start it it would stall and die but if i waited till it quit flashing it was fine but now it locks the gear shift dies when you use the bli=nkers switches between milage and trip then resets it i have ruled out battery alternator and i dont have a remote starter can anyone help me it would be greatly appreciated