GMC specific DTC OBD2 code: P1820 Internal Mode Switch Circuit A Low
GMC specific DTC OBD2 code: P1819 Internal Mode Swtich No Start, Wrong Range
GMC specific DTC OBD2 code: P1818 TFP Valve Position Switch-Drive Without Drive Ratio
GMC specific DTC OBD2 code: P1817 TFP Valve Position Switch-Reverse With Drive Ratio
GMC specific DTC OBD2 code: P1816 TFP Valve Position Switch-Park/Neutral With Drive Ratio
GMC specific DTC OBD2 code: P1815 Transmission Range Switch-Start In Wrong Range
GMC specific DTC OBD2 code: P1814 Torque Converter Overstressed
GMC specific DTC OBD2 code: P1813 Torque Control
GMC specific DTC OBD2 code: P1812 Transmission Over Temperature Condition
GMC specific DTC OBD2 code: P1811 Maximum Adapt And Long Shift