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Snap-on Scanner live data

Posted By: Dartslantsix

Snap-on Scanner live data - 04/15/22 02:48 AM

I'm using a Snap-on scanner for the first time and I'm confused when looking at the live data.
Most of the sensors make sense, but some don't. Is there a place that lists in plain English what the abbreviations for the sensors mean?
For example the attached picture shows a graph for "1/1 O2S(V)". (car is 2004 PT Cruiser GT) My assumption is that this is the upstream oxygen sensor and the units are volts. However, from what I'm seeing online, the O2 sensor should oscillate between 0-1 volts. This graph shows 2.54v-3.39v. So, I'm wondering if I'm misunderstanding what the graph is telling me. There are a couple other lines of data that pertain to the O2 sensor, but none of them read between 0-1 volts.

Edit:
Just found this:
https://www.snapon.com/Files/Diagno...municationSoftwareManual_EAZ0025B01H.pdf

I'll have to start digging through it.

Attached picture IMG_1693.JPG
Posted By: Dcuda69

Re: Snap-on Scanner live data - 04/15/22 03:16 PM

Most likely that o2 sensor is actually a wide band A/F sensor. Wide bands work between 2.0 and 4.0 volts. 3,2ish represents stoicheometric ratio. Below that is rich and above that is lean. Scanner is just listing it as an o2 sensor. Not 100% sure on that particular vehicle but that would be my guess. twocents

P.S. The additional lines of data pertaining to o2 is likely heater information
Posted By: CMcAllister

Re: Snap-on Scanner live data - 04/15/22 05:58 PM

Originally Posted by Dartslantsix
I'm using a Snap-on scanner for the first time and I'm confused when looking at the live data.
Most of the sensors make sense, but some don't. Is there a place that lists in plain English what the abbreviations for the sensors mean?
For example the attached picture shows a graph for "1/1 O2S(V)". (car is 2004 PT Cruiser GT) My assumption is that this is the upstream oxygen sensor and the units are volts. However, from what I'm seeing online, the O2 sensor should oscillate between 0-1 volts. This graph shows 2.54v-3.39v. So, I'm wondering if I'm misunderstanding what the graph is telling me. There are a couple other lines of data that pertain to the O2 sensor, but none of them read between 0-1 volts.

Edit:
Just found this:
https://www.snapon.com/Files/Diagno...municationSoftwareManual_EAZ0025B01H.pdf

I'll have to start digging through it.


O2 sensors range from 0-5 volts depending on the O2 in the exhaust. AF ratio sensors work differently. I doubt an 04 PT has an AF sensor.

Spray a little carb cleaner in the intake. Then pull a vacuum hose to create an air leak and watch the results.

Posted By: cudaman1969

Re: Snap-on Scanner live data - 04/15/22 08:15 PM

What type scanner do you have? I bought mine off the Snapon truck used and have no manual either
Posted By: Dartslantsix

Re: Snap-on Scanner live data - 04/16/22 01:38 AM

Quote
What type scanner do you have? I bought mine off the Snapon truck used and have no manual either

The scanner I am using is a Solus. The link I have in the original post covers most of what I needed, so check that out.

As to my original question, after reading the linked manual, Chrysler feeds the O2 sensor 2.5v, so it oscillates between 2.5-3.5. So, my graph is reading correctly. I need to adjust the scale and take another look at the data with the engine at 2000 rpm. I suspect this O2 sensor is on its way out.

Lots to learn!

-Dave
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