2002 Trailblazer, Reduced Engine Power comes on. Engine seems to be running properly.

Hello
Whenever this warning light comes on it is indicating that a problem has been sensed by the electronic sensors of the engine and or the transmission and the on board computer (called the PCM) has limited the engine power to avoid further damage to the system components like the engine and transmission. What needs to be done (and is stated in the owners manual) is take the car in to a GM dealer or a suitable trusted service center and have the electronics tested for the fault codes that are stored in the system whenever the light is turned on that would indicate what part of the electronic controls (this can be a sensor, wiring or the computer, it can also be a mechanical fault) has malfunctioned. Due to complex nature of the system guessing will waste your time and money, there are at least 100 different faults that will trigger this warning. Once the technican has the fault codes and has driven the car they can begin diagnostics of the problem(s) indicated by the stored fault codes.