Why reduced engine power light is on? on 2002 Oldsmobile Bravada

I heard a load noise when I started vehicle this morning then it stopped. I let it warm up and then drove about 35 miles today in extremely cold conditions. As I was pulling into work, the "reduced engine power" light came on. I turned it off to go into work. I am concerned that it may not start again. This is first time this light has come on. The service engine light has been on for a few weeks also.

Asked by for the 2002 Oldsmobile Bravada
Usually the reduced power is in conjunction with the traction control. It needs diagnosed, preferably with a Tech2 scanner to diagnose the fault. It should still start.
Thank you for your response. I am not sure what a Tech2 scanner is.
It is the tool that GM uses for diagnostics. Myself and other independent shops have it as well.