I recently got the code P0135 on my 2002 Accord, and proceeded to follow the directions given in this tutorial I found online.
http://troubleshootmyvehicle.com/hon...-sensor-test-2
I performed test 2(Checking the Heater Sensor Ground wire) and got an extremely low voltage, basically none. I know now that the ground wire may be open, but im not sure where to begin. I know the ground is within the ECU, yet I don't know if I should evaluate the ground there or try to find where the wire may be open.
Any help would be very much appreciated. Thanks!

02 Honda Accord SE
Auto

 

C1 from the PCM is the connection. So do you have continuity from C1 to the BLK/WHT on the O2?

What is/was the resistance between pin 3 and 4 of the O2 side?

 

Checked the resistance on the O2 side, read OL. There is continuity between C1 and BLK/WHT.
Although I'm still worried about the ground wire for the Heater. Does the car have to be on completely for it to register as a ground, since it's going through the PCM?

 

If you went across the O2 and got "open" - then the heater inside the O2 is broken....replace the O2 and retest, but that is just me.