Lamp out message on dash remains on

Rapid flashing when either signal is selected is indicative of poor ground circuit on front or rear for the signal that's flashing... Have helper push brake pedal with headlights on and left signal selected.. Look at both 'front' & rear to see what's happening!.. Also possible internal flasher problem.. Scan test may be needed.

i have had cases were final drive module located on tipm shorts out due to high resistance coming from blinker circuit thats malfunctioning, usually low side driver circuit fails and shorts out light bulb socket, if light socket looks like it has heat damage replace LF light bulb socket for blinker.