STATE OF THE ART
Cambiare explains how lambda sensors work, and how
they’ve come a long way since the ’70s.
Lambda sensors are vital to ensuring a vehicle
reaches optimal performance and aid in
reducing harmful carbon emissions. They do
this by monitoring the air-to-fuel ratio within
the exhaust and relaying the information to
the engine control unit (ECU).
STANDARD LAMBDA SENSOR *
LEAN
0 WHAT’S CHANGED?
10 environmental
20
14.7:1
With
legislation becoming
AIR/FUEL
RATIO
stricter, it’s important for automotive
*For visual purposes only
1 Signal voltage
2 Isolates the ground
of the signal to
reduce signal noise
3 Heating element so
the sensor operates
faster and more
reliably
Detects by how
much the air-fuel
ratio is too rich or
lean
LEAN
HIGHLIGHTS INCLUDE
0.45
0.45
0
5
5-WIRE LAMBDA SENSOR *
5
RICH
HOW DO THEY DO IT?
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), the sensor produces
STANDARD LAMBDA SENSOR *
a voltage of around 0.9 volts. In contrast,
0.9
when
RICH the mixture is too lean (insufficient
fuel), it produces around 0.1 volts. A perfect
stoichiometric ratio produces 0.45 volts. To
imperfect
mixture ratios, the
STOICHIOMETRIC
0.45
0.45 compensate for
(14.7:1) by using more
ECU adjusts the fuel mixture
or less fuel depending on what’s needed.
4
5
0.9
The perfect air-to-fuel ratio is known as the
stoichiometric ratio. For a petrol engine the
ideal ratio is 14.7:1, meaning 14.7g of air is
needed for every 1g of fuel. This ratio ensures
optimum fuel efficiency, thus producing a
minimal amount of emissions.
3
4
technology to evolve in order to reduce
emissions of pollutants such as nitrogen oxide
(NOx), carbon monoxide (CO), total and non-
methane hydrocarbons.
STOICHIOMETRIC
(14.7:1)
LEAN
10
20
14.7:1
AIR/FUEL RATIO
*For visual purposes only
5-WIRE LAMBDA SENSOR *
5
VN 54 | APRIL – JUNE 2019 7
LEAN
STOICHIOMETRIC
(14.7:1)
2.35
0
RICH
10
14.7:1
AIR/FUEL RATIO
*For visual purposes only
20
Cambiare lambda sensors cover over 12,000
STOICHIOMETRIC
2.35 which includes the 5-wire
applications,
(14.7:1)
sensors to cover popular applications.
These include:
• VE381391
RICH
0
- BMW 5 Series
520d 2.0 (2010-16)
20
10
14.7:1
• VE381389
AIR/FUEL RATIO
- Audi A3 Sportback
2.0 only
(2012>)
*For visual purposes
• VE381483
- Vauxhall Corsa 1.2 (2009-14)
• VE381388
- KIA Sportage 1.7 (2010-15)
All Cambiare parts are OE quality, backed by
2-year/30,000-mile warranty and catalogued
on the Cambiare website (www.cambiare-ve.
com) as well as the F:Drive and MAM Autocat.
The Cambiare technical team can be reached
on 0845 543 8280 for additional guidance.
Speak to your local FPS representative for full
details.