t4pizza

Hope someone can answer this. My taillights went out on the R350 (left first and then right) and the substitute lights came on. I replaced the bulbs and the substitutes are still on and the error messages are still on. I reset the lighting to factory settings with no luck. I have taken these bulbs out and put them back in every way imaginable with no luck. Finally I tried the taillight bulbs in the reverse lights, and sure enough they work, so it is not the bulbs. Is there something I am missing? Would hate to take this into the dealer if it is something easy. Thanks in advance for any help.