ESP malfunctioned while driving on highway: tires braked several times rapidly on one side without warning, making car difficult to control. Immediately took foot off gas and had to steer out of a small fishtail. At the time I was driving at normal speed, not cornering aggressively or anything, on a smooth dry road. In heavy traffic or on a wet road this could have resulted in a crash. On just a couple occasions shortly before this occurred, while going around corners at highway or near-highway speeds there was a sensation that the steering direction suddenly "slipped" a notch, with a sort of thunk from the tires. At the time I attributed it to unseen road bumps, but after experiencing the more serious failure I realized it was the same asymmetrical braking just on a smaller scale. No warning lights gave any indicator of this dangerous sensor fault. During the most serious incident, the ESP light flickered briefly but that is the only time any lights appeared at all. I would expect this system to "fail safe" by deactivating, rather staying active and risking loss of control. Dealer garage said the problem "might" be the ESP sensor yaw rate sensor (G202) but can't guarantee that will fix it. I found several reports online of others experiencing loss of control due to Audi A3 ESP malfunction: 1) https://www.audi-sport.net/xf/threads/esp-driving-me-nuts.225172/ 2) https://www.audi-sport.net/xf/threads/yaw-sensor-g202-replacement-location.350445/ 3) www.vask.org.nz/index.php?topic=41577.0

- San Francisco, CA, USA