Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P029D, P02A1, P02A5, and P02A9 are Type A DTCs.
The control module commands the engine to operate in the Reduced Engine Power mode.
The message center displays Reduced Engine Power.