Circuit Description
The Mass Air Flow (MAF) meter uses a platinum hot wire. The hot wire air flow meter consists of a platinum hot wire, temperature sensor and a control circuit installed in a plastic housing. The hot wire air flow meter works in principle that the hot wire and temperature sensor located in the intake air bypass of the housing detect any changes in the intake air temperature.
The hot wire is maintained at the set temperature by controlling the current flow through the hot wire. This current flow is then measured as the output voltage of the air flow meter.
The circuit is constructed so that the platinum hot wire and temperature sensor can provide a bridge circuit with the power transistor, and controlled so that the potential of A and B can remain equal in order to maintain the set temperature.
HINT:
After confirming DTC P0100, P0102 or P0103 use the hand-held tester or the OBD II scan tool to confirm the MAF ratio from the "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL".