Checking Mass Air Flow When Under Partial Load

Checking Mass Air Flow When Under Partial Load

The manifold absolute pressure (MAP) sensor in the control module will affect engine performance if it shows too low a value.
The manifold absolute pressure sensor does not affect engine performance but the mass air flow sensor value will be compared with the MAP sensor value later on in the course of fault diagnosis.





- Drive the car in top gear with a steady high engine load.
- Driving uphill is recommended.





- Read value: Airmass Deviation from Calculated (Trionic).
- State what the diagnostic tool shows:

15% to 25% - Checking Air Leakage Before Flap

Other value - Checking Air Mass Variations