oscillating or solid beep? normal runnin' conditions solid is overheat,.oscillating is oiler relatedl or (if efi) water in fuel.... if either of these sound with just tha key on ya got a problem......
with key on only
solid beep wil be either a grounded/bad over heat sensor or bad oiler module (usually tha culprit).. any signal going thru tha module will oscillate unless module is bad.. that's is only function..
oscillating beep usually is low oil in motor tank or bad low oil sensor in motor tank...possible but not likely tha module...