Posted 17th December 2020
Air Mass Meters measure the air entering the engine and convert this into an electronic signal used by the Engine Control Unit (ECU) to determine engine load and calculate correct fueling and ignition timing. A small platinum sensor element is maintained at a constant temperature regardless of air flow. This is achieved by monitoring the resistance of the heated sensor, as more air flows, the sensor is cooled, and a feedback loop supplies more current to maintain the temperature. This current draw is then converted into a relative signal which is sent to the ECU. An additional ambient temperature sensor allows for correction of the signal due to intake air temperatures changes which have a huge impact on the output.
It is difficult to diagnose a faulty Air Mass Meter on symptoms alone, other faulty components such as Fuel Pump, Fuel Pressure Regulator and Vacuum System can all present similar symptoms, this is why it is important to troubleshoot the Air Mass Meter before replacing components.
On newer vehicle models, the car computer can produce precise diagnostic trouble codes (DTCs) that will pinpoint the cause of the problem.
SMP Europe’s range of Air Mass Meters are available in Intermotor, Lucas, Lemark and FuelParts brands.