Resolved ... I had the same issue with my Toyota 4Ruuner and Toyota Tundra. Only 1 can be programmed and the other loses it. I have a Genie garage door (with rolling code) and what finally worked is when i reset the garage door opener by pressing and holding the learn button for 10 seconds. Then programmed the regular remote control that comes with the garage door. And then reprogramming both cars as i did before. This time though both kept the code.