I went threw this with my 2011 Chevy 1500 4.3L V6 this past March 2013 when I had about 52,000 miles, I was on my way south. My truck started to flash the message, "Service Stabilitrak, Service Traction Control, Engine Power is Reduced" Messages. Both my Check engine light and low traction warning lights were on. Truck idled very poorly(misfired) top speed was approx. 40mph really sluggish to get to that speed and the trans shifted really hard. Limped it to a Chevy dealer and they stated two codes P2135 and P0121 due to my failed Throttle Position Sensor(TPS). They replaced the sensor, reprogrammed the ECU and reset the Idle. I now have over 60,000 miles and that issue has never returned. My truck gave no sign or warning before the sensor failed, at-least it didn't leave me stranded and I was able to limp it to my hotel and to the dealer in the morning.These types of topics are rare, but they're very important when they are needed.
It's way too late for the OP in this thread to get back in touch with us, but I'm curious if anyone else has gone through this.