SENSING
EMISSIONS
CAMBIARE explains how vehicle
electronics play a part in reducing
a vehicle’s carbon footprint.
Effective reduction of pollutants goes beyond ensuring that emissions
control systems such as the catalytic converter (CAT) and diesel
particulate filter (DPF) are up to scratch. Vehicle electronics and
engine management systems are integral in optimising a vehicle’s
LAMBDA SENSORS
Lambda sensors are best known for monitoring air-to-fuel ratio
(stoichiometric ratio) and relaying the information to the ECU when
fitted just before the CAT (pre-CAT) in the exhaust system. They are
vital in ensuring a vehicle’s optimal performance and aid in reducing
harmful carbon emissions.
Traditional lambda sensors do the job of regulating the stoichiometric
ratio. However, it has limitations in providing the ECU with an
accurate reading of how rich or lean the air-to-fuel ratio is. Whilst
traditional lambda sensors are still commonly used today, the
technology has advanced to cater for 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 instantly 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. They also have a heating element
to speed up the sensor reaching the required temperature.
Additionally, lambda sensors can also be fitted after the CAT (post-
CAT) to monitor its ability to remove harmful pollutants from exhaust
gases. In the event that the CAT is not performing adequately, the
lambda sensor will alert the ECU which will log a fault code and
illuminate the engine management warning light.
efficiency and in turn, lowering its carbon footprint. Vehicle
electronics and engine management specialist, Cambiare shares some
points on the significance of sensors in reducing emissions.
KEEPING TABS ON EMISSIONS
As CATs and DPFs are significant parts of the vehicle’s emissions
control system, it is important to ensure that they are well maintained
to ensure optimum performance and longevity. Exhaust gas
temperature sensors (EGTS) and exhaust gas pressure sensors
(EGPS) play integral roles in protecting the DPF.
EGTS
The EGTS protects a vehicle’s
exhaust system from overheating,
which is especially important
when a 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 to clear the
exhaust and release it safely.
The EGTS monitors the heat
produced from the exhaust,
supplying the ECU with a signal
to ensure that the temperature
reached does not fall outside a
vehicle’s safety parameters.
EGPS
EGPS are often differential sensors that measure the pressure of
gas between the intake and outtake of the DPF. By measuring the
pressure, the EGPS communicates 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.
COMPREHENSIVE RANGES FROM CAMBIARE
Backed by a 2-year/30,000-mile warranty, Cambiare parts are fully catalogued on the Cambiare website, www.cambiare-ve.com, MAM Autocat and
the F:Drive. For more information, please speak with your local FPS representative.
VITAL NEWS ISSUE 47
VEHICLE ELECTRONICS 7