Diagnosis of Air Mass Meter
Diagnosis of Air Mass MeterThe output voltage of the air mass meter is a measure of air mass flow. The diagnostic routine compares the mass flow measured by the air mass meter with a calculated mass flow, derived from engine speed and throttle valve position. If the measured mass flow from the air mass meter is above a threshold value from the characteristic map, a fault is detected. If the measured air mass flow from the air mass meter is lower than a threshold value from the characteristic map a fault is detected. The diagnostic routine commences after end-of-start is reached and finishes after a time delay. The following flow chart shows the structure of the diagnostic function:
