The Mass Air Flow (MAF) sensor measures the flow of air which passes through it in a given time. PCM uses this information to monitor the operating condition of the engine for fuel delivery calculations. A large quantity of air movement indicates acceleration, while a small quantity indicates deceleration or idle. MAF sensor produces a frequency signal, which cannot be easily measured. Diagnose sensor using procedures on this chart.

Code P0101 will set when the following conditions are present.

Engine is running.
No MAF signal for over 4 seconds.

With Code P0101 set, PCM will use a default value for airflow based on throttle position, IAC motor position and engine speed. PCM will illuminate Malfunction Indicator Light (MIL).

NOTE: Test numbers refer to numbers on diagnostic chart.

This step checks to see if PCM recognizes a problem.
Voltage reading at sensor harness terminal "A" of less than 4 volts or greater than 6 volts indicates a fault in circuit No. 492 (Yellow wire), or poor connection.
Verifies that both ignition feed voltage and a good ground circuit are available.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Code P0101, MAF Sensor Circuit: Notes

Use the Manual With the Right Hardware

When to See a Mechanic

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