0-5 volts into O2 sensor pin on ecm
- Thread starter Pablo
- Start date
I don't think it will actually fry anything but it could and it definitely won't do what you want. The stock O2 input is 0 to about 1 V, not 0 to 5 V. You can try a simple voltage divider but it will be a little tricky because the O2 input has a pullup resistor of about 200 K (from memory, could be 100 K or higher), and I don't know how low the output impedance of your wideband is. Try getting 2 K and 8 K resistors (1/4 or 1/8 watt is fine), connect them together and connect this point to the ecm o2 input, connect the other end of the 2 K to ground, and the other end of the 8 K to your wideband output. That will multiply the 0-5 V output by (2 K / (2 K + 8 K)) = 0.2, giving you roughly a 0-1 V output. The roughly is because of those other impedances I mentioned earlier, which may mess up things by 5-10%. After you get it wired up and your scan tool running, use a good 10 megohm input impedance digital voltmeter to measure the voltage at the wideband output and the ecm input to see how close you are. If you have to you can adjust the resistor values to get closer or just make up your own calibration.
Yep, I thought of that shortly after i posted this originally, but someone told me that it wouldnt work because the ECM is providing 5 volts and the IAT was just resistance to gnd... something like that. Maybe I misunderstood him because that still seems odd to me.
no big deal anyway as i have found that my WB has a programmable output, i can scale say 10:1 afr to 16:1 afr from 1 to 0 volts.
I will be doing that shortly
no big deal anyway as i have found that my WB has a programmable output, i can scale say 10:1 afr to 16:1 afr from 1 to 0 volts.
I will be doing that shortly
