I found this on Tesla's website just now. I hadn't seen it before, or discussed here; specifically, the "pump the brake pedal" portion. Roadside assistance & tech support | Tesla Motors Recognizing the key If Model S does not detect its key within the cabin, hold the brake pedal down and place the key directly below the 12 volt accessory power outlet. If the key is not detected within a minute, pump the brake pedal several times. If the issue persists, contact us.