– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit fuse
– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit open shorted to ground
– Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection
– Faulty Powertrain Control Module (PCM)
– Possible higher than usual fuel Consumption
Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. The faster the heated oxygen sensor reaches that temperature the faster the sensor will start sending an accurate signal to the Powertrain Control Module (PCM).
In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The PCM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The PCM controls the heater element circuit by allowing current flow to ground.
The PCM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.