One problem related to engine cooling system has been reported for the 2006 Cadillac STS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 Cadillac STS based on all problems reported for the 2006 STS.
Car stopped running while traveling on a freeway doing 70 mph with no warning. Total loss of power, a/c, brakes, steering, and windows (loss of all power assisted functions and accessories).