Mass Air Flow Sensor: Diagnosis

If the mass air flow sensor develops a fault, three different diagnostic trouble codes may be generated:

• If the mass air flow sensor does not send any frequency at all to the control module, diagnostic trouble code P0100 will be generated. The cause may be a break in one of the leads.
• If the frequency is too low, trouble code P0102 will be generated. The cause may be a major leak between the mass air flow sensor and the throttle body or an internal fault in the mass air flow sensor.
• If the frequency is too high, trouble code P0103 will be generated. The cause is an internal fault in the mass air flow sensor.