What does a NOx sensor do and what happened to your car when it fails?

Time: 2022-05-04

The nitrogen oxygen sensor (NOx sensor) is used to measure the nitrogen oxygen concentration in the exhaust gas of the engine, thus to meet the needs of the closed-loop control of the engine after-treatment system and the needs of the on-board OBD diagnostic system. There are 2 NOX sensors in the diesel Euro VI after-treatment system, intake one and exhaust one, working together to realize the more accurate closed-loop control logic and improve fuel economy.

Intake NOx sensor detects the NOX concentration and oxygen concentration in the original exhaust gas of the engine, and sends signals to the ECU for calculating and controlling the urea injection amount and DPF regeneration; while exhaust NOx sensor mainly detects the NOx concentration of the exhaust gas and calculates the conversion efficiency to realize the closed-loop control of urea injection.

When the NOx sensor starts to work, it needs to be heated to the working temperature and self-checked. If passes the self-check, it then starts to work. When working, the NOx sensor transmits the NOx value in the exhaust gas to the ECU in real time, and the ECU detects whether the NOx value in the exhaust gas exceeds the standard through a set of nitrogen oxide monitoring program, so as to adjust the injection of the urea fluid.

What happens when your NOx sensors fails?

As an important part of the aftertreatment system, once the NOx sensor fails, it will have a series of effects on the vehicle:

1. Cause multiple engine fault lights to light up, and there will be relevant fault records saved in the control unit.

2. Cause the diesel control system to be in an open-loop state, the emission data cannot be fed back accurately, thus the engine control unit cannot adjust the emission precisely, making the vehicle in a state of over-emission. Keep being in over-emission state will shorten the life of the exhaust emission treatment devices.

3. Cause the diesel combustion control disordered, resulting in weak acceleration, idling jitter, and inability to start the vehicle.

Therefore, high-quality NOx sensors are essential to the normal operation of the vehicle. Use high-quality NOx sensors can help reduce the vehicle failures, prolong the service life of automobile emission treatment devices, and thus save vehicle operating costs. As a 14-year auto parts exporter and an SCR manufacturer, SYSOLIN is committed to providing customers with high-quality and low-cost nitrogen and oxygen sensors.

- With core technology patents, we produce ceramic chips not only for self use, but also supply for NGK in Japan.

- With developed supply chain, our nitrogen oxygen sensors have a lifespan equivalent to the original products, up to 2400 hours, and the prices are only half of them.

- Adopt import control unit.

- The protocols of NOx sensors are updated simultaneously with the European vehicle emission protocols.

We provide NOx sensors for DAF, SCANIA, VOLO, IVECO, MAN, MERCEDES-BENZ, CUMMINS, BMW, Volkswagen and other brands of vehicles. Welcome your inquiry.

Ester Yin

Whatsapp/Skype: +8619872070626

Email: foton@chinasonglin.cn