P0101 GMC Possible Causes
- Faulty mass air flow sensor
- Intake air leaks
- Dirty mass air flow sensor
- Dirty mass air filter
- Mass air flow sensor harness is open or shorted
- Mass air flow sensor circuit poor electrical connection
First diagnose P0101 GMC code
Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded terminals.
P0101 GMC Tech NotesBefore replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.
Diagnosing GM Digital Mass Air Flow Sensors P0101
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Cost of diagnosing the P0101 GMC code
Labor: 1.0The cost of diagnosing the P0101 GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
When is the P0101 GMC code detected?The P0101 code is set when the Powertrain Control Module (PCM) detects that the Mass Air Flow (MAF) sensor frequency is below a predetermined value.
P0101 GMC Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
- Engine stall
- Engine running rough
- Excessive fuel consumption
- Excessive smoke
P0101 GMC MeaningThe Mass Air Flow (MAF) sensor measures the amount of air ingested by the engine. The direct measurement of the air entering the engine is more accurate than calculating the airflow from the Manifold Absulte Pressure (MAP), the Intake Air Temperature (IAT), and the engine speed (speed/density). The MAF sensor has a battery feed, a ground, and a signal circuit.
The MAF sensor used on this engine is a hot wire type. This engine uses the MAF sensor in order to measure air flow rate. The MAF output frequency is a function of the power required to keep the air flow sensing elements (hot wires) at a fixed temperature above the ambient temperature. Air flowing through the sensor cools the sensing elements. The amount of cooling is proportional to the amount of air flow. The MAF sensor requires a greater amount of current in order to maintain the hot wires at a constant temperature as the air flow increases. The MAF sensor converts the changes in current draw to a frequency signal read by the Powertrain Control Module (PCM). The PCM calculates the air flow (grams per second) based on this signal.
The PCM monitors the MAF sensor frequency. The PCM determines if the sensor is stuck low, stuck high, not providing the airflow value expected for a given operating condition, or that the signal appears to be stuck based on a lack of signal variation expected during the normal operation. This diagnostic tests for too low an airflow rate.
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