P0100
DTC P0100 Mass Air Flow Circuit MalfunctionDTC P0102 Mass Air Flow Circuit Low
DTC P0103 Mass Air Flow Circuit High
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 meter, 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 air flow 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 remains equal to maintain the set temperature.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunctions Thresholds:
Component Operating Range:
If there is a defect in the MAF meter or an open or short circuit, the voltage level will deviate outside the normal operating range. The ECM interprets this deviation as a defect in the MAF meter and sets a DTC.
Example: When the sensor output voltage 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 intelligent tester to confirm the MAF (to reach the MAF menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY).
Wiring Diagram:
Step 1:
Step 1(Continued)-3:
Step 4:
Step 5-6:
Step 7:
INSPECTION PROCEDURE
HINT: Read freeze frame data using the intelligent 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.