Hi, my max threw a SEL the other night, just one code: P0051 HO2S heater control circuit low (bank 2, sensor 1). I'm looking at the O2 sensor locations posted on the sticky and in the diagram the code corresponds to is bank 1, sensor 1, not bank 2. Anyway, not sure what circuit low means, bad connection? Any help would be appreciated. Thanks.

 

I see what you mean with the sticky and the FSM. I would go with the FSM which says bank 2, sensor 1.

Assuming that you don't have a wiring problem, which you should check for, the O2 sensor is bad. The sensor has some kind of coating on it that wears off/out.

 

Thanks, I'm going to run through the wires and check, but just to verify, bank 2, sensor 1 is the one that is blue, first one on the left that is connected to front of the engine, is that correct? Can't find the part# atm, is the sensor the same for the 00-01 and 02-03 max?

 

P0051 HO2S heater control circuit low should not cause driveability issues but the light with stay lit until u replace the 02 sensor. 02 sensors work in a heat range that is incredibly high and each sensor has an internal heater to help get the sensor to operating temperature faster. that code means the heater inside the sensor is not working, but the sensor itself is performing as it should

 

Thanks, checked the sensor and wires, looked fine, and the SEL went away on it's own yesterday after driving with it on for about 4 days. Not sure what may have happened, but I bought a new O2 sensor already, may just hold off on installing it and see if the code comes up again.