Bosch 4-pin lambda (oxygen) sensor connector carries heater power and the Nernst cell signal wires. The heater brings the sensor to operating temperature quickly for accurate rich/lean measurement.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | Heater+ | Sensor heater positive 12V | PWR |
| 2 | Heater- | Sensor heater negative | GND |
| 3 | Signal+ | Lambda signal positive output | ADC |
| 4 | Signal- | Lambda signal ground return | GND |
Bosch 4-pin lambda (oxygen) sensor connector carries heater power and the Nernst cell signal wires. The heater brings the sensor to operating temperature quickly for accurate rich/lean measurement.