http://www.regalgs.org/obd2.htm DTC P0050 HO2S Heater Circuit Bank 2 Sensor 1 Past that, I have few clues how to proceed. It is a heated O2 sensor (bank 2 is closest to firewall?) not sure whether sensor 1 is the upstream or downstream sensor. Check that the heater connection has continuity. Easy way to reset all the codes is to pull the controls B+ fuse in the under-hood fuse block for 20 seconds. reset the codes and see if it comes back. Oppie ('01 LW300)
DCT P0050 Circuit Description The heated oxygen (HO2S) bank 2 sensor 1 is threaded into the cylinder 2, 4, 6 exhaust manifold (cylinders 2, 4, 6 are closest to radiator). The sensor is equipped with a heater element to decrease the amount of time required to enter closed loop fuel control. The ECM controls the heater by pulsing circuit 551 to ground. When the heater is commanded Off (circuit not grounded), the voltage level at the ECM should be high (ignition voltage). When the heater is commanded On (circuit grounded), the voltage level at the ECM should be low. The ECM heater feedback circuit uses a pull-up voltage (1.6-3.6 volts), which allows the ECM to individually differentiate between an open, short to ground or short to voltage. DTC P0050 will set if the ECM detects an open heater control circuit when the engine is running.
