Sensors - NOx

 

Sensors - NOx

 

 

Air pollution caused by several forms of gases such as methane, carbon dioxide and nitrous oxide was once the order of the day. Some gases even cause ozone depletion. As a result, authorities continue to set stricter emissions regulations and the cost of buying diesel vehicles continues to rise.

Car manufacturers are now designing some NOx sensors into cars that notify the driver when emissions are not as clean as they should be.

 

What are NOx sensors?

As the name suggests, Nox sensors are components used to measure and calculate the amount of nitrogen oxides in exhaust gases. The amount of nitrogen oxides in the exhaust gas shows whether there is enough oxygen during the combustion process. This helps the catalytic converter to work properly.

Their main function is to reduce harmful exhaust by-products and ensure a clean environment. You might be wondering "what happens if a Nox sensor fails"? This sensor will cause the powertrain control module to display the check engine light on the dashboard. You may also experience low engine power, poor acceleration and low fuel consumption.

Nox sensors come in different models and vary from vehicle to vehicle. Older vehicles may include DFP, turbocharger, SCR catalytic converter and upstream Nox sensor.

Modern vehicles come with upstream and downstream Nox sensors. They measure exhaust emissions and send the data to the engine control module. The ECM calculates how much fuel to send to the combustion chamber.

Both upstream and downstream Nox sensors are mounted on the exhaust pipes. They work differently and offer different benefits. The upstream sensor measures the Nox output of the engine and the downstream sensor calculates the Nox emissions from the SCR catalytic converter.

How does an NOx sensor work?

A Nox sensor is a component of the SCR system that measures the amount of Nox in an exhaust system. This helps the SCR know the correct level of ammonia or urea to provide better fuel economy and less harmful emissions into the atmosphere.

 

 

In addition to measuring the amount of nitrogen oxides in the exhaust gas, some Nox sensors also monitor the mass of the exhaust flow.

A state-of-the-art Nox sensor on modern cars shows compounds that react with nitrogen oxides. These compounds are known as catalysts and are usually made from activated carbon, titanium oxide and other base metals.

These compounds send a voltage correlated to the level of nitrous oxide. The higher the nitrogen in the exhaust gas, the stronger the voltage.

Nox sensors with less sophisticated compounds work for exhaust gas monitoring and oxygen scavenging and Nox concentration analysis.

Symptoms of NOx sensor failure 

Like others car sensors, sensors Nox can break down. Whether you're experiencing Nox sensor failure symptoms on DD15 engines or BMW Nox sensor failure symptoms, here are the main signs you should watch out for:

- High fuel consumption

- Hard idling

- Irregular acceleration

• Soot accumulation
• Check engine light

 

What causes NOx sensor failure?

 

Some factors can cause a NOx sensor to fail. Here are the likely causes of sensor failure:

1. Accumulation of soot:Because of the location of these sensors, it is not surprising that soot build-up can damage them. While soot buildup is a sign of a faulty Nox sensor, it is also a common cause.
2. Burnt or damaged cables:a burnt or damaged wiring harness can be the root cause of NOx sensor failure. In such a case, a virtual inspection will identify the problem.

The internal connectors that read NOx levels may be faulty.

There may be other causes, but these are the common ones you should keep in mind. A visual inspection may be all you need to trace the cause of the NOx sensor fault.