Advanced Diagnostics

Advanced Diagnostics - DTC P0101: Mass Airflow (MAF) Sensor Circuit Range/Performance Problem










General Description
The mass airflow (MAF) sensor directly measures the amount of intake airflow into the engine, and the powertrain control module (PCM) controls the fuel injection based on the measured value. The manifold absolute pressure (MAP) sensor measures the intake manifold pressure, and the PCM calculates the amount of intake airflow from the MAP sensor output and the engine revolutions. The PCM compares the MAF sensor output (amount of intake airflow) and the amount of intake airflow calculated from MAP sensor output. If their difference is too large (in the malfunction area), the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
The difference between the amount of intake air measured by the MAF sensor and the amount of intake air calculated from the MAP sensor output is out of the normal area for at least 5.0 seconds.

Driving Pattern






1. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on.
2. Let the engine idle for at least 5 seconds.
3. Drive the vehicle at a steady speed of 40 mph (64 km/h) or more for at least 5 seconds.

- When freeze data is stored, drive the vehicle under those conditions instead of Driving Pattern step 3
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.