194 LED's work just fine in the rear lights...been running them for years. Make sure you don't break the plastic tabs or the bulb assembly will fall out of its slot. I'd be surprised if the newer models don't permit LED's like the older models...but YMMV.Pop the lenses/assemblies out with a screwdriver. They are a little tricky, be careful. Then the back twist out of the housing and the bulb can be replaced. LEDs will not work, at least not the ones available at parts stores. They didn't in mine anyway.
I found I also had a blown fuse. They are not mentioned in the manual but they are on the same fuse as the back driver side tail light. If you tail light is working then the fuse is probably fine.