Advanced Diagnostics

Advanced Diagnostics

DTC P0101: Mass Airflow (MAF) Sensor Circuit Range/Performance Problem (Engine Type: K20Z3)






General Description
The mass airflow (MAF) sensor directly measures the amount of intake airflow into the engine, and the engine control module (ECM) controls the fuel injection based on the measured value. The manifold absolute pressure (MAP) sensor measures the intake manifold pressure, and the ECM calculates the amount of intake airflow from the MAP sensor output and the engine revolutions. The ECM 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 ECM detects a malfunction and a DTC is stored.

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 seconds.

Driving Pattern

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

- When freeze frame data is stored, drive the vehicle under those conditions instead of Driving Pattern 2.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.


Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the ECM memory. If the malfunction recurs during the next (second) drive cycle, the MIL comes on and the DTC and the freeze frame data are stored.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs. The MIL, the DTC, the Temporary DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.