Air Flow Meter/Sensor: Testing and Inspection

MASS AIR FLOW SENSOR (MAFS)

INSPECTION

FUNCTION AND OPERATION PRINCIPLE




Mass Air Flow Sensor (MAFS) is a hot-film type sensor and is located in between the air cleaner and the throttle body. It consists of a tube, a sensor assembly and honey- comb cell and detects intake air quantity flowing into the intake manifold. Air flows from the air cleaner assembly through the honeycomb cell and over the hot film element. At this time, heat transfer is generated by convection and this sensor loses its energy. This sensor detects the mass air flow by using the energy loss and transfers the information to the PCM by frequency. The PCM calculates fuel quantity and ignition timing.

Specification:

SPECIFICATION

Circuit Diagram:

CIRCUIT DIAGRAM

COMPONENT INSPECTION
1. Check the MAFS visually.
- Mounting direction correct.
- Any contamination, corrosion or damage on connector.
- Air cleaner's clogging or wet.
- MAFS cylinder's deforming or blocking by any for engine material.

2. Check any leakage on intake system and intercooler system.