About a month ago I noticed that the Service Stabilitrak light and message would pop up on occasion and then go away. This happened once or twice a week. About a week ago I started the truck up and the Check Engine light came on along with the Service Stabilitrak light and a message warning that the engine was in "reduced power mode." The truck wouldn't go faster than about 55 km/h and when idling at stop lights the truck would rev and lurch forward similar to a cylinder misfire. Upon letting go of the brake the truck would violently jerk forward.

I took the truck to a friend who is a GMC mechanic. He told me that the Throttle Position Sensor would require replacement. This would usually cost about $1,200 or possibly more. However, he informed me that there is a Special Coverage (number 11273) pertaining to it being recalled. However, it's a "replace if fail" recall, so GMC will only cover it under warranty if the part fails within a certain amount of time. The special coverage only applies if the truck has less than 193,000 km, or until I believe he said the year 2021. My truck had about 20 km remaining before it wouldn't have been covered!

Once the part was replaced the truck has been working great with no other problems.

According to the warranty work order the following work was done to correct the problem: Warranty Code: 11EN35187730 "Performed special coverage 11273 and replaced the throttle position sensor cover and reprogrammed the ECM." Parts: No. 12589235 - Seal 033360 No. 19259452 - Sensor KI 033390

engine light comes on, message says,, engine power reduced, traction control needs servicing, , Vehicle loses power, will only go about 10 km/hr. if you turn off and let sit , it may reset.. may take a few tries. it seems to be happening when it is quite cold. ie. winter about -20 degrees C. .. once it warms up above about 87 degree C... seems to run fine, . very dangerous if this happens in traffic. not to mention your truck is not running when it is this cold. still working on the fix. many theories at this point. one thing everyone agrees with is this has nothing to do with the traction system ,, except it won't work in this condition.

Update from May 8, 2017: there is a fix. this is the engine Throttle Position sensor. And it has a special extra long warranty.. 10 years or 193,000 kms. , as per bulletin #11273B, , 32 Boos Taylor, Wa 94 1.30.

Sounds like this happens a lot... but I would suggest you check a dealer, I don't think your local garage man would know about this warranty or check, since GM has not exactly advertised this problem, nor have they done a recall like they should have.