An introduction to sensors
INSTANT EXPERT
The considerable computing power within modern cars would be useless without sensors. With so many different types fitted to modern engines, Rob Marshall looks at how DIYers can examine, test and replace them.
Compared to those trundling around the UK road network, when this magazine debuted, current vehicles are computers on wheels. While it remains true that most of today’s cars retain internal combustion engines, and therefore, a degree of mechanical integrity, they are still controlled electrically. Much of this is down to necessity. With our roads becoming considerably busier, engines had to become more fuel-efficient, reliable and powerful, while being less polluting. More accurate means of metering fuel and ignition were made possible only after replacing relatively imprecise mechanical distributors and carburettors with more accurate electronic ignition and fuel injection.
Early injected cars tended to use a single computer/Electronic Control Unit, whereas current cars employ multiple ECUs that communicate together. Our investigations into both ECUs (August 2023 issue) and data networking (November 2023 issue) explain how all of these systems work. Yet, without some kind of measuring hardware, there would be little point in all of this processing power.
Enter the sensor
With the need to detect anything from movement to pressures and temperatures, a modern motorcar possesses hundreds of different sensors. As space precludes us from including all of them, this feature’s focus is to provide a basic introduction to sensors that monitor primarily the engine, fuel system and exhaust gases. Should one of these sensors develop an o
