O2 voltage reading 0.00 volts during live data hook up

[seanagins]

I hooked up a code reader. An old cen tech from harbor freight. I didn't have any cel or trouble codes. Just wanted to monitor live data. I found that my O2 voltage was at 0.00 volts. It never changed. Any leads to what I should be looking for? I see that I have 2 O2 sensors equipped on my 1997 ford ranger xlt 4x2 automatic with 4.0liter v6. Please help. Any and all advice is appreciated.

 

[SenorNoob]

If you don't have a light and it does work (Check it when you turn the key to run without starting.), then I'd say the code reader just doesn't speak exactly the same language as the truck.

 

[seanagins]

I got under the truck when it cooled down and got a better look. I have 3 oxygen sensors. 2 upstream and 1 downstream.

 

[Dirtman]

Like @SenorNoob said, some code readers (mainly cheap ones) simply cannot read the data properly. The upstream o2 sensors (B1S1 and B2S1) change voltage rapidly as they sense the changing fuel mixture, cheap scanners often do not have a fast enough refresh rate to see this fluctuation so you'll just get a dead reading. The downstream o2 sensor (B1S2) stays at a fairly constant voltage since it is just reading exhaust post catalytic converter but, sometimes even this data is just not available and the scanner will again show dead info. With no check engine light, ignore it. The PCM is much smarter than a 10 dollar scan tool.

 

[seanagins]

Like @SenorNoob said, some code readers (mainly cheap ones) simply cannot read the data properly. The upstream o2 sensors (B1S1 and B2S1) change voltage rapidly as they sense the changing fuel mixture, cheap scanners often do not have a fast enough refresh rate to see this fluctuation so you'll just get a dead reading. The downstream o2 sensor (B1S2) stays at a fairly constant voltage since it is just reading exhaust post catalytic converter but, sometimes even this data is just not available and the scanner will again show dead info. With no check engine light, ignore it. The PCM is much smarter than a 10 dollar scan tool.

Well, the scan tool is cheap, but it reads voltage on the 02 bands for my friends Dodge Hemi. He thought it was his scanner as well not reading with my pcm, but it reads his voltage when we hooked it up to his truck. I am having no cel, but driveability problems under hard acceleration at operating temperatures.

 

[Dirtman]

Turn the key to the run position (not start) does the check engine light come on, and then go out once the truck is started?

 

[seanagins]

CEL illuminates like it is suppose to (KOEO) then goes out when you start the engine (like it is suppose to). Scanner shows no codes.

 

[Dirtman]

Then I would have no problems ignoring the live data. If all 3 o2 sensors showed zero voltage to the PCM the CEL would be on, you would have about 9 DTCs and the engine would be stuck in open loop mode. Work on diagnosing by the symptoms in this case. For about 25 bucks you can get an ELM 327 USB adapter and if you have a windows laptop you can use forscan (free software). This setup gives you about the best scanner you can use on a Ford short of a dealer level device.

 

[seanagins]

Then I would have no problems ignoring the live data. If all 3 o2 sensors showed zero voltage to the PCM the CEL would be on, you would have about 9 DTCs and the engine would be stuck in open loop mode. Work on diagnosing by the symptoms in this case. For about 25 bucks you can get an ELM 327 USB adapter and if you have a windows laptop you can use forscan (free software). This setup gives you about the best scanner you can use on a Ford short of a dealer level device.

Okay, I downloaded FORscan. Just the free version to start off with.

KOLSOL ELM327 USB V1.5 with Switch modified for Ford ELMconfig Forscan CH340+25K80 chip HS/MS-CAN

KOLSOL ELM327 USB V1.5 with Switch modified for Ford ELMconfig Forscan CH340+25K80 chip HS/MS-CAN

www.worldobd2.com

on the elm327 usb adapter, will the above link work?

 

[Dirtman]

There is a free version for phones, this is not full forscan. If you downloaded the windows version on a laptop your good. It's free, you just need to renew the license every 2 months. The paid version is no different you just don't have to keep updating your license. No extra features.

Elm327 adapters are tricky, lots of garbage out there that doesn't work.

This is the one I use and can verify works.

https://www.amazon.com/gp/product/B01F0GVBWY/?tag=959media-20

If you wanna spend some more, this one is supposed to be forscan's official device but I have not used it and it costs more.

https://www.amazon.com/dp/B081VQVD3F/?tag=959media-20

 

[seanagins]

There is a free version for phones, this is not full forscan. If you downloaded the windows version on a laptop your good. It's free, you just need to renew the license every 2 months. The paid version is no different you just don't have to keep updating your license. No extra features.

Elm327 adapters are tricky, lots of garbage out there that doesn't work.

This is the one I use and can verify works.

https://www.amazon.com/gp/product/B01F0GVBWY/?tag=959media-20

If you wanna spend some more, this one is supposed to be forscan's official device but I have not used it and it costs more.

https://www.amazon.com/dp/B081VQVD3F/?tag=959media-20

I did download the windows version on a laptop. Beings that I downloaded the free version, how do I renew every 2 months? I will research the elm327 usb adapters some more. Thanks for all your replies and efforts.

 

[Dirtman]

Go here... https://forscan.org/forum/extlic.php sign up, then download the free license.

 

[seanagins]

Go here... https://forscan.org/forum/extlic.php sign up, then download the free license.

I did that already.... I downloaded Forscan already.

 

[Dirtman]

Then your good to go. In 2 months it will expire and you just go download the license again.