I just uncovered the 179 in June due to heart surgery in April.  I checked everything out and found that the LED taillights had partially failed.  I ordered out new though the dealer.   About half the led's had failed in each light.  The lights are completely sealed including the back, so I don't think it was moisture that caused the problem.  I did find that the back of the light had a gob of caulk attached to it in roughly the shape of the failed led's on the circuit board.  I think the failure happened due to  this caulk causing the circuit board to overheat.  Led's don't produce a lot of heat, but I always drive with the lights on.  I will seal around the lights with silicone but, remove the caulking.  I think the newer pods use a different taillight. 

 

lark f-150 2015 R-179