Below is video tutorial about O2 or Oxygen sensor heater. On the Oxygen sensor, there are two wire with the same color. One color for O2 heater (+) and the other is O2 Heater (-). Oxygen sensor heater will always controlled by ECM but the control circuit will very depend on the manufacturer. There are 3 ways of the ECM to control the O2 sensor heater.
One is using power relay controlled by the ECM. On the newest system, O2 heater (+) and O2 heater (-) are provided with ECM. The ECM detect so plane short circuit by reading the feedback wire at the heater controller side. For further information about the O2 or Oxygen sensor heater, watch the entire video.