Self Study Program 358 – Hot-film Air-mass Meter HFM 6

VAG SSP 358. This self-study programme explains the basics of measuring intake air mass, familiarises you with the hot-film air-mass meter HFM 6 and helps you understand how it works.

Due to the further development of standards and laws for exhaust emissions in vehicles, components with improved measuring accuracy are constantly needed. Therefore a new generation of hot-film air-mass meters are now being used for engine management.

Simply converting the exhaust gases after combustion is not enough to meet these laws and standards, instead they have to be kept as low as possible by means of efficient combustion.

Furthermore modern engines deliver an increasing amount of power with the same or lower fuel consumption.

In addition to other measures, the exact measurement of the intake air by the air-mass meter also helps meet all of these requirements.


  • Basics of air-mass measurement
    – Temperature and air pressure
    – Effect of temperature and air pressure on the air mass
  • Basics of combustion
    – Air-fuel ratio
    – Emissions guidelines
  • Hot-film air-mass meter HFM 6
    – Task
    – Location
    – Design
  • Sensor element
    – Design
    – Bypass channel
    – Measuring method
    – Return flow detection
    – Transfer of air-mass signal to the engine control unit
    – Intake air temperature sensor
  • Service
    – Diagnosis
  • Test Yourself

The self-study programme shows the design and function of new developments.
The contents will not be updated.
For current testing, adjustment and repair instructions, refer to the relevant service literature.

Language: English
Format: PDF
Pages: 20

Self Study Program 358 – Hot-film Air-mass Meter HFM 6 Design and Function PDF free online