XTOOL PIDs

Hello everyone. I am new to using scan tools and new to the forum. I am just a DIYer and get much of my info from research and trial and error. I had a question that is probably a remedial one....

If I am looking at Oxygen sensor PIDs, I have two that are suppose to be reading the same things, but they are different values.

1. 2/1 O2S Sensor voltage....reads ~0.6 Volts
2. 2/1 O2S Sensor Output voltage.....it reads ~ 2.4 volts

This is on a 2005 RAM 4.7L. From what I understand they are all Narrow Band sensors. I am just confused as to why the scanner shows these 2 values? Why/How does it show a value greater than 1V on a PID? 

Thank you.  

As I understand it, one PID reflects the oxygen sensor voltage plus the bias voltage applied to the signal, and the other PID is a normalized 0-1v scale. And even if that's not exactly accurate, it's always been good enough for me to fix my cars. I always just look at the 0-1v PID because it's familiar.

Chrysler/Dodge/Jeep/Ram products like your '05 Ram will have a few different PIDs going for the upstream sensors. I grabbed a capture from another Ram 4.7L as an example:

 

Like Noah said, the '2/1 O2S Sensor Output voltage' is just the raw signal voltage with the sensor ground bias present. Most CDRJ oxygen sensors use a 2.5V bias on the sensor ground circuit, so 2.5V becomes dead lean, and 3.5V is full rich. That's where the '(0-1V)' PID comes in - it automatically translates the O2 signal into the 0-1V range we're used to.

SD has a great video explaining how the bias circuit works:



I'm guessing that your '2/1 O2S Sensor voltage....reads ~0.6 Volts' is actually the 2/1 O2 Goal (0-1) (V) in the capture above. O2 Goal is a stupid PID. It's not any kind of oxygen sensor signal, but actually the PCM's downstream fuel control trim (based on the downstream 1/2 or 2/2 sensors). O2 Goal values above .45V means the PCM is adding fuel based on the downstream sensor, less than .45V means subtracting.