Circuit/System Description
For an overview of the component/system, refer to: Heated Oxygen Sensor Description and Operation
| Circuit | Description |
|---|---|
| Signal - Terminal 4 | The control module input circuit has an internal resistance connected to 1.8 V. |
| Signal - Terminal 3 | The control module input circuit has an internal resistance connected to ground. |
| Component | Description |
|---|---|
| B52 Heated Oxygen Sensor | An oxygen sensor is an electronic device that measures the proportion of oxygen (O2) in the exhaust gas being analyzed.In addition to the hot exhaust gas, heated oxygen sensors have a resistor heating element to minimize the time required for the sensor to reach operating temperature. The ECM monitors the temperature and turns the heater on as necessary. |
| K20 Engine Control Module | The control module controls a series of actuators to ensure optimal engine performance. The control module does this by reading values from a variety of sensors, interprets the data and adjusts the engine actuators accordingly. |
When the engine is started, the ECM operates in an open loop mode, ignoring the HO2S signal voltage while calculating the air to fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 40 to 1050 mV. Once sufficient HO2S voltage fluctuation is observed by the ECM, closed loop is entered. The control module uses the HO2S voltage to determine the air to fuel ratio. An HO2S voltage that increases toward 1000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.In addition to the hot exhaust gas, heated oxygen sensors have a resistor heating element to minimize the time required for the sensor to reach operating temperature. The ECM monitors the temperature and turns the heater on as necessary.