This sounds like you have got a problem with Ground 303, which is located on the left hand A pillar. In the diagrams down below I have included the backup and exterior lighting diagrams for your vehicle as well as the location of Ground 303 for you. Please inspect the ground and make sure that it is clean, tight, corrosion free, and making good metal to metal contact, and get back to us with what you find out.
Images (Click to enlarge)
Sunday, February 16th, 2020 AT 3:51 PM