Air Mass Sensors

Air Mass Sensors
Air Mass Sensors

Masterparts offers high-quality air mass sensors for a wide range of vehicle makes and models.

What does an air mass sensor do in a car?

An air mass sensor is critical to the optimal functioning of a vehicle’s engine. It measures the intake of air to enable the precise injection of fuel into the combustion chamber.

In addition to maintaining the correct air-fuel ratio in the fuel injection system, the air mass sensor regulates the flow of exhaust gases.

The component consists of a heat sensor built into an airflow passage. The sensor can be one of two designs:

  • hot-wire air mass sensor (typically in older model cars)
  • hot-film air mass sensor (a modern component containing a film-like sensor plate rather than an electrical wire).

How does an air mass sensor work?

How does an air mass sensor work

Diagram source: Apogeeweb

An air mass sensor uses electrical current to measure the inflow of air into the intake valve.

Depending on the type of sensor, either the wire or heating resistor plate is heated to between 120 and 180°C above the temperature of the intake air.

As the air flows over the sensor, it lowers its temperature and a higher electrical current is required to maintain the heat.

The electrical charge heating the sensor to the original 120 to 180°C is used to determine the air mass flowing into the engine.

An electronic signal conveys this data to the engine control unit (ECU). The ECU uses the information to precisely calculate how much fuel to inject.

A video by the Motorservice Group, How does an air mass sensor work?, provides a 3D-animated view of the process.

Signs of a faulty air mass sensor

When an air mass sensor is faulty, the ECU either under- or over-estimates the amount of fuel required for combustion.

Miscalculations manifest in a variety of symptoms, from jerking or stalling during acceleration to rough idling, difficulty starting the engine and poor fuel efficiency.

Black smoke billowing out of the exhaust, a stuttering or surging engine and a check engine alert on the dash are also signs of a malfunctioning air mass sensor.

High-quality air mass sensors for sale in South Africa

Masterparts offers a range of air mass sensors from leading international brands.

Components are designed to advance automotive requirements for optimal performance, fuel efficiency, driveability and emissions.

At Masterparts, our consultants can help determine which air mass sensor is the best match for your vehicle.

Where to get air mass sensors from Masterparts

We offer door-to-door delivery. Alternatively, visit any of our branches across South Africa or in Windhoek, Namibia.

Air mass sensors in and around Cape Town:

Air mass sensors in KwaZulu-Natal:

Air mass sensors in Namibia:

Masterparts offers a comprehensive range of engine, suspension, steering, braking and electronic parts for thousands of different car makes and models. Contact us if there’s a part you need and we’ll do our best to assist.


Call us on 021 657 5757 or complete the form below to get a quote.

    Current ProjectAir Mass Sensors