Emission Control

Emission Control

Vehicle electronics specialist, Cambiare, explains how vehicle electronics and engine management systems are key components in reducing a vehicle’s carbon footprint.

With the existing laws set by the Euro 6 legislation, the pressure for vehicle manufacturers to invest more resources into developing better vehicles that comply with the legislative guidelines shows no sign of relenting. Emission pollutants such as nitrogen oxide (NOx), carbon monoxide (CO), total and non-methane hydrocarbons, as well as various particulate matters were expected to be reduced with the use of modern automotive technology.

Effective reduction of pollutants goes beyond ensuring that emissions control systems such as CATs and DPFs are up scratch. Vehicle electronics and engine management systems are integral in optimising a vehicle’s efficiency and, in turn, lowering its carbon footprint. With a wide array of products that support the lowering of harmful emissions, vehicle electronics specialist, Cambiare, shares some points about the significance of lambda sensors, exhaust gas temperature sensors and exhaust gas pressure sensors.

Lambda sensors

By the simplest definition, lambda sensors monitor the air-to-fuel ratio within the exhaust and relay the information to the ECU. Lambda sensors are vital to ensuring a vehicle’s optimal performance and help 5-wire lambda sensor to reduce harmful carbon emissions.

The perfect air-to-fuel ratio for optimum engine efficiency is known as the stoichiometric ratio. The stoichiometric ratio for a petrol engine is 14.7:1 in which 14.7g of air is needed for every 1g of fuel. This ratio allows for optimum fuel efficiency, wasting less fuel and, in turn, producing the lowest amount of emissions.

Traditionally, lambda sensors produce a voltage signal based on the volume of air detected in the exhaust. If the mixture is too rich (too much fuel supplied), the sensor produces a voltage of around 0.9V. When the mixture is too lean (insufficient fuel supplied), it produces around 0.1V. A perfect stoichiometric ratio produces 0.45V. To compensate for imperfect mixture ratios, the ECU adjusts the fuel mixture by adding more fuel when the mixture is lean or using less fuel when it is too rich.

Whilst a traditional lambda sensor does the job of regulating the stoichiometric ratio, it was unable to provide the ECU with an accurate reading of how rich or lean the air-to-fuel ratio was. Lambda sensor technology needed to keep up with the demand of the tighter Euro emission standards.

With the introduction of the 5-wire lambda sensor, the ECU is not only supplied with a signal that relays if the air- to-fuel ratio is running too rich or too lean, it also conveys by how much. This precise information is swiftly sent to the ECU to allow the vehicle to rectify the air-to-fuel ratio more efficiently and effectively and increase the overall performance of the vehicle.

Exhaust Gas Temperature Sensors (EGTS)

In comparison to lambda sensors, exhaust gas temperature sensors are relatively new. An EGTS measures the temperature of the exhaust gas which is monitored by the ECU to help prevent long-term damage to components.
The EGTS protects a vehicle’s exhaust system from overheating, which is especially important when a diesel particulate filter (DPF) regenerates. The DPF reduces the amount of soot that is released with exhaust fumes by collecting and storing it within the filter. Over time, soot accumulates within the filter and needs to be incinerated at extremely high temperatures in order to remove it from the exhaust system and release it in the surrounding air, safely.

Typically, exhausts run at temperatures in excess of 900°C in order to successfully regenerate the DPF. At these extreme temperatures, thermal overload becomes a huge risk. The EGTS monitors the heat produced from the exhaust, supplying the ECU with a signal to ensure that the temperatures reached do not fall outside a vehicle’s safety parameters.
Due to the extreme conditions that EGTS operate in, they are prone to damage during exhaust component replacements. Therefore, they need to be replaced simultaneously with a DPF and/or exhaust, as opposed to waiting for the dashboard warning light to illuminate.

Timely replacement of an EGTS prevents damage to the DPF and subsequent engine damage. Cambiare’s EGTS use two types of technology – positive temperature coefficient (PTC) and negative temperature coefficient (NTC). PTC increases the resistance with the increase in temperature. NTC works in an opposite fashion with the sensor producing less resistance as the temperature of the exhaust increases.

Exhaust Gas Pressure Sensors (EGPS)

EGPS are differential sensors that measure the pressure of gas between the intake and outtake of the diesel particulate filter (DPF). By measuring the pressure, the EGPS communicate a voltage signal to the ECU. This enables the system to detect the level of soot and particles collected within the DPF. This information enables the ECU to monitor and detect when regeneration is required for efficient emissions reduction.

As a result, a malfunctioning sensor can cause a variety of problems which impacts the increase of oil consumption and emissions. If the sensor is faulty, DPF regeneration can increase unnecessarily, leading to the shortening of the DPF lifespan.

Cambiare ranges

Cambiare covers a wide range of applications within its portfolio of lambda sensors and EGTS. With more than 100 EGTS and 500 lambda sensors in stock, products are available from FPS via same/next-day delivery.
Also available from Cambiare:
• ABS Sensors
• Air Mass Sensors
• Lambda Sensors
• Camshaft Sensors
• Crankshaft Sensors
• Exhaust Gas Temperature Sensors
• Exhaust Gas Pressure Sensors
• Ignition Coils & Leads
• EGR Valves
• Fuel Pumps
• Fuel Injectors
• Throttle Bodies

Backed by a two- year/30,000-mile warranty, Cambiare parts are fully catalogued on the company’s website, www.cambiare- ve.com, MAM Autocat and the F:Drive.

For further information from Cambiere, click here.

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