I searched and didn't see a thread about this anywhere here so I thought I'd bring it up. After discovering that the trailer backup lights didn't work with my 2010 4wd TRD Sport I confirmed the problem was in the truck not the trailer. Long story short is that Toyota failed to install the needed relay to run the trailer backup lights. I found this out over at Tacoma World, confirmed that mine was missing the relay, replaced it and voila, trailer b/u lights are working. This seems to affect many Tacos for several years around 2010. The relay should be in a socket behind the glovebox, just to the right of the cabin filter box. If yours is missing, I'd love to hear back from you. I think Toyota needs to do something about this because if you are not aware of the situation, you can spend a lot of time and frustration trying to chase this one down, believe me, I did.
Anybody else? Even if you don't have a trailer with b/u lights, if your Taco has the factory towing package, that relay should have been included and Toyota needs to know about it so they can issue a notification at least to their service depts.
Anybody else? Even if you don't have a trailer with b/u lights, if your Taco has the factory towing package, that relay should have been included and Toyota needs to know about it so they can issue a notification at least to their service depts.