Dodge P1820 Internal Mode Switch Circuit A Low Description OBD-II Trouble Code Description for P1820 Dodge Internal Mode Switch Circuit A Low PSA OBD-II Trouble Code Description for P1820 Dodge Transmission transfer case clockwise shift relay coil circuit failure VAG OBD-II Trouble Code Description for P1820 Dodge Pressure Contr.Solenoid 2 Short to B+