Conditions for Setting the DTC: P2251
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 that the HO2S 1 reference ground circuit is open.
- DTC P2251 sets within 1 second when the above condition is met continuously, or within 10 seconds when the above condition is met cumulatively.