I started having this issue a couple years ago with my 96 Camry with 300k miles on it. Due to the age of the car I decided to just leave it and it has been driving great. I have put probably 20k miles on it while this code was on. As far as I can tell the only consequence is slightly reduced highway mpg (about 2 mpg less). I think the ECM does not even attempt to lock the torque converter when you have this code, so if you have an older car that you just need to get you around it probably isn't worth fixing. On my V6 Camry the solenoid is located on top of the valve body inside the transmission, so you would have to drop the pan and remove the valve body to access it. The solenoid is not cheap either, so I don't think I am going to spend that much time just to gamble and see if it might fix the issue. This code alone shouldn't make any difference on your emissions besides the slight mpg drop, but if you live in state that automatically fails you for a check engine light then you can usually just reset it...