have you properly cleaned out the engine bay box?
first time i did it, i only cleaned a little , did nothing.
second time round, cleaned every contact that i could, all the big fuses, the white R connect at the bottom.
first turn of the key after locking/unlocking the car. red imob went out.
now ive got a new UCH that i dont now need lol.
atleast ive got a spare N3 if mine ever gives up
check the fuses in the dash aswell. i had a little 5amp one looking abit worst for ware. ( door elumination light , car with doors open pick on the cover )