Structure and inner electrical connection
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 BMW X3, 2016 BMW X3, 2015 BMW X3, 2014 BMW X3, and 2013 BMW X3. However, it is still accessible from the selected car via links, so may be relevant.
Voltage is applied at the at the pump cell. This means that oxygen ions are pumped into the measurement cell until a voltage of 450 mV settles between the electrode of the measurement cell. The resulting pump current is the measured variable for the fuel-air ratio. This enables the oxygen sensor emissions control to set any desired air/fuel ratio in the combustion chamber.
| Index | Explanation |
|---|---|
| 1 | Oxygen sensor heating |
| 2 | Reference cell (Nernst cell) |
| 3 | Measurement cell (Nernst and pump cell) |
PIN REFERENCE
| Pin | Explanation |
|---|---|
| PWM | Pulse-width modulated activation of the oxygen sensor heating |
| Kl. 15N | Battery voltage, Terminal 15 |
| U1 | Pump voltage at the reference cell |
| R | Trimming resistor |
| Kl. 31 | Virtual earth |
| U2 | Nernst voltage |