Wiring Wideband O2 Sensors

[mike_sno]

I wired my wideband O2 Sensor as well to the AC Pressure sensor. I found this video to be very helpful to get maximum accuracy of the analog signals.

Unfortunately no matter what I try, VCM Scanner does not read my Serial input.

 

[Ross]

What signal is it that you are trying to get in on the serial input? Since you put your wideband on your AC Pressure sensor, that signal will be on the canbus... just need to find the AC pressure sensor, and apply some math to it. I have seen that formula here on the forum...

 

[mike_sno]

I have the Innovative LC-2 Wideband controller, connected via Serial to my laptop. Was logging a a drive with the innovative software. In HP Tuners I have added the serial channel for the Innovative LC-2, but it disappears as soon as I start recording. I tried all kind of things I have read in HP Tuners forum and saw on youtube, but can't make it to record directly in HP Tuners.

The AC pressure sensor is a workaround. I was hoping to eliminate the Digital/Analog conversion of the LC-2 followed by a Analog/Digital conversion by the ECU.

The math and calibration of the signals is not the problem.

 

[Ross]

You can see the wideband data with the innovate software, but not on HP Tuners?
A Tripp Lite USB to Serial Converter helped me get the O2 data. I had a cheap serial to USB converter that was causing me data issues. Still, sometimes I have to reboot the laptop to get Windows to recognize the USB converter.
Here is my setup.

 

[mike_sno]

You can see the wideband data with the innovate software, but not on HP Tuners?
A Tripp Lite USB to Serial Converter helped me get the O2 data. I had a cheap serial to USB converter that was causing me data issues. Still, sometimes I have to reboot the laptop to get Windows to recognize the USB converter.
Here is my setup.

That's correct. I can see the Wideband in the innovate Software but not on HP Tuners.

I used a good USB Serial converter. That thing was the only one which worked on my milling machine. The connection to the innovate Software is stable. https://amzn.to/4bFEJVs (Affiliate Link)

 

[mike_sno]

Here is the reason why I want to read the Signal directly from the Serial port instead of going over an analog input. And a way to get the most accuracy out of the analog output.

Analog Input Calibration:

1. Set up VCM Scanner to simply log the AC Pressure Voltage. I used 5 decimal cells.
2. Program the Wideband controller to send a flat voltage. E.g. 3V
   
   
3. Run VCM Scanner for like 3 or 4 minutes. Which gives you over 1000 counts in the cell. The Average voltage should be stable.
4. Note the commanded and measured minimum, -maximum and -average voltage.
5. Repeat Step 2 -4 with different Voltage settings. I suggest using at least something like 1 V and 4V. If you want to go crazy: I did a complete set from 1V to 4.5V in 0.5V steps and filled it in the table below.
   
   
6. Now I saw that the Analog Input gets really high in the tolerance below 2V. That being said, I went ahead and used the Range 2-4.5V from now going forward.
7. A bit of simple linear algebra and the incline and zero point were located. See attached Excel if you want to know more.
8. Now I set up a userdefined math sensor to correct the Voltage reading to match what the Wideband controller spit out. The formula for correcting my Voltage readings is [7101.10] * 0.990972 - 0.0842
   
   
9. With this user parameter I tested the reading again. Programm the wideband sensor to whatever Voltage in the range you selected. For me it worked out. HP Tuners has now a corrected Voltage reading.
10. Depending on your preference you can now select a AFT or Lamda range and continue with the math to calculate the desired value.

I did not test if the reading is much different between running on battery or when the engine is running. I put a power supply to simulate a running engine and could not see a difference in the reading.