Rep Power: 0

02 civic d17a1 with p0135 code. Sensor 1 heater circuit malfunction. I have my 12v but no ground from ECU. I checked for ground at the ECU connector so it's not a wiring issue and is not a sensor issue (so please don't ask about the sensor). I need to know what the ECU is looking for that determines if it needs to run the o2 heater or not. Is it looking at the ECT sensor? I just need to figure out what commands the ECU to turn the ground on for the heater circuit for O2 sensor 1.

 
Rep Power: 222

Still going to say sensor if the harness side is good

 
Rep Power: 0

Did you not read my post? How is a bad sensor that is brand new and ohms out just fine going to make the computer send a ground to make it work? You don't understand how the system works evidently. It's like telling me to replace the light bulb because the switch isn't turned on. Heater circuit isn't going to work period without a 12v and ground, end of story.

 
Rep Power: 222

I did read it......

What brand is it and where was it purchased from?

 
Rep Power: 367

this is the first time you are telling us that the sensor is brand new?
chill down, that info is important to omit.