Conditions for Setting the DTC: P0629
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.
The ECM detects the fuel pump relay control circuit is shorted to voltage.
The DTCs set when the above conditions are met for more than 4 seconds or a cumulative of 50 seconds.