In article <1119641268.12308316e37be8940f0746f443d9d4e5@teran ews>,
says...
> 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)
>
> "Tuneup" > wrote in message
> ...

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.