BMW 550i 2017-present Emissions & Sensors Specifications

The NOx (Nitrogen Oxide) sensor monitors the levels of nitrogen oxides in the exhaust gases. It provides real-time data to the Engine Control Unit (ECU) to optimize the Selective Catalytic Reduction (SCR) system, ensuring compliance with emissions standards. The sensor operates at a temperature range of -40°C to 900°C and has a response time of less than 2 seconds.

Oxygen sensors in the BMW 550i typically have a service life of 60,000 to 90,000 miles. However, this can vary based on driving conditions and fuel quality. Symptoms of a failing O2 sensor include poor fuel economy, rough idling, and increased emissions. It is recommended to inspect the sensors during routine maintenance and replace them if diagnostic trouble codes (DTCs) indicate a fault.

The lambda (O2) sensors in the BMW 550i operate within a voltage range of 0.1V to 0.9V. A reading below 0.45V indicates a lean air-fuel mixture, while a reading above 0.45V indicates a rich mixture. The sensors are critical for maintaining optimal combustion efficiency and reducing harmful emissions.

Yes, a malfunctioning emissions sensor, such as the NOx, O2, or particulate matter sensor, can trigger the Check Engine Light. The ECU continuously monitors these sensors for irregularities. If a fault is detected, the CEL will illuminate, and a corresponding DTC will be stored in the system. Immediate diagnosis and repair are recommended to prevent further damage.

The particulate matter (PM) sensor measures the concentration of soot particles in the exhaust stream. It works in conjunction with the Diesel Particulate Filter (DPF) to ensure efficient regeneration and compliance with emissions regulations. The sensor has a detection range of 0 to 100 mg/m³ and operates at temperatures up to 500°C.