Traveling on hwy 35 in dallas texas and message appeared on instrument cluster "reduced power mode". vehicle speed dropped to 20 mph (posted speed was 70 mph). had to have vehicle towed to dealership and a fix has not been determined. the dealer so far has charged me $900 and it did not fix it.this same problems been posted on gm forums, gm truck forums with these same results. there are hundreds or maybe thousands of complaints for this issue. it is very unsafe. *tr