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Setting up uaEFI , trying to get the wbo2 to work, went through the process of update the firmware and turn on all the necessary can bus and o2 stuff. The board came back and indicated that the heating has fail. Use a volt meter look at the two heater pins, there is no voltage between H+ and H-, there is voltage on the pin H+ to ground, Look to me the H- did not turn on. Double checked all the wiring and setting, could not find what may cause the issue. btw, I update to 2023 firmware for the o2. Do I need to update to the 2025 firmware? Appreciate your help. thanks.

I have turn on force heater on already. Do you have to have RPM before the heater will turn on?

midengc8 wrote: ↑

Sat Nov 15, 2025 3:49 pm

I have turn on force heater on already. Do you have to have RPM before the heater will turn on?

I am sorry if my English is not great. Does not "option to force heater for bench test" from link above answer your question?

Hi AndreyB,

Thank you for the response, your English is great, is my understanding of the link a bit fuzzy.
I followed instructions on the link and still I could not make it work, I must be missing something that caused the heater to fail. Please see the screen shoot of the before and after.

before after
Thank you for your help.

What do I need to do to re update the wbo2 since the update button is not highlighted? Want to start over to see if I can solve the heating issue.

Measured between H- to H+ on the wide band o2 is 8.5v when the controller is heating up the sensor. Is this the correct value? the test is done on the bench with 12v power supply.

To clarified 8,5v between H- to H+ was with the o2 sensor not connected.