Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls And Fuel - 6.2L - DTC P1255 To DTC P2635 >> DTC P2120, P2122, P2123, P2125, P2127, P2128, or P2138 >> Action Taken When the DTC Sets