P0102

DTC P0100 MASS OR VOLUME AIR FLOW CIRCUIT
DTC P0102 MASS OR VOLUME AIR FLOW CIRCUIT LOW INPUT
DTC P0103 MASS OR VOLUME AIR FLOW CIRCUIT HIGH INPUT

CIRCUIT DESCRIPTION

DTC Detection Condition:

The Mass Air Flow (MAF) meter measures the amount of air flowing through the throttle valve. The ECM uses this information to determine the fuel injection time and provide a proper air fuel ratio. Inside the MAF sensor, there is a heated platinum wire exposed to the flow of intake air. By applying a specific current to the wire, the ECM heats this wire to a given temperature. The flow of incoming air cools the wire and an internal thermistor, affecting their resistance. To maintain a constant current value, the ECM varies the voltage applied to these components in the MAF meter. The voltage level is proportional to the airflow through the sensor. The ECM interprets this voltage as the intake air amount.

The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with the power transistor controlled so that the potential of A and B (see illustration) remain equal to maintain the set temperature.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Conditions:

Typical Malfunction Thresholds:

Component Operating Range:

If there is a defect in the sensor or an open or short circuit, the voltage level will deviate from the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets a DTC. Example: When the sensor voltage output is less than 0.2 V or more than 4.9 V and if either condition continues for more than 3 seconds, the ECM will set a DTC.

This monitor runs for 3 seconds (the first 3 seconds of engine idle) after the engine is started (1 trip detection logic).

HINT: After confirming DTC P0100, P0102 or P0103, use the hand-held tester to confirm the MAF (to reach the MAF menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY).

Wiring Diagram:

Step 1-2:

Step 3-4:

Step 5-6:

Step 7:

INSPECTION PROCEDURE

HINT: Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was LEAN or RICH, and other data from the time the malfunction occurred.