I was driving my 2012 Camry down the road when the Brake light, ABS light, and Traction/Stability control light suddenly came on, followed by a hydraulic whining noise for approximately 10 seconds and the brake pedal going soft. I pulled off and restarted the car, and the lights went out but the brake pedal remained soft.

I took it to the dealer, where they informed me the code was C1246 - Master Cylinder Pressure Sensor Malfunction. I was informed to repair this they would be replacing the Stop Light Switch. Yes, this struck me as odd too, especially given I had confirmed my brake lights still functioned at the time it was dropped off. Either way, the switch was replaced and on receipt of my car everything seemed to be working fine again.

This is frustrating for a couple reasons. The first being an intermittent failure of the switch that turns on your stop lights could disable your ABS and ESC/TCS, causing a less experienced to potentially lose control over the vehicle in an emergency situation. Second is that the switch that controls your stop light coming could fail, possibly leading to you being rear ended. Finally, the fact a $18 part (Toyota P/N 84340-09070) left me without my car for 5 days (time it took dealer to see it was 3 business days, plus 2 for the diagnosis and repair) is a personal inconvenience. With the digitized, computer based control systems on modern cars this shouldn't be surprising a minor part can cause such frustration, but still is disappointing when ti does happen.

Update from Nov 21, 2014: Well at 32,000 miles it happened again. Limped to the dealer after parking it for the night and this time the lights came back on that ride. After consulting with Toyota, Toyota ordered my dealer to have the ABS Actuator replaced. Had the car been out of warranty this would have been a $2600-3000 job from what I can gather. Toyota and my dealer handled it very well and I weigh their response to these kind of issues as heavily as the car's actual reliability, but I'm extremely disappointed it happened again, especially after I suspected the original repair was a band aid or misdiagnosis.