Technical Description
Intermittent or erratic circuit for mass or volume air flow
What does that mean?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to OBD-II equipped vehicles with a mass airflow sensor. This includes brands such as Ford, Mercedes, Peugeot, Toyota, Honda, Citroen, Nissan, VW, Jeep, Chevrolet, Dodge, etc. While it is a generic code, the specific repair steps may vary depending on the make and model of the vehicle.
The MAF (mass air flow) sensor is a sensor located in the engine air intake tract downstream from the air filter. It is used to measure the volume and density of air being drawn into the engine. The MAF sensor only measures a portion of the air entering and uses that value to calculate the total volume and density of air being ingested.
The powertrain control module (PCM) uses the MAF sensor reading, along with other sensor parameters, to ensure proper fuel delivery for optimal power and fuel efficiency.
This P0104 diagnostic trouble code (DTC) indicates that there is an intermittent or erratic fault detected in the Mass Air Flow (MAF) sensor or circuit. The PCM detects that the actual MAF sensor frequency signal is not within the normal expected range of the calculated MAF value.
Note: Some MAF sensors also have an air temperature sensor, which is another value used by the PCM for optimal engine operation.
Related MAF circuit trouble codes include P0100, P0101, P0102, and P0103.
Photo of a MAF sensor:
What are some possible symptoms?
Symptoms of a P0104 code may include:
What are some potential causes?
Potential causes for this trouble code may include:
Note that other codes may be present if you have a P0104. You may have misfire codes or O2 sensor codes, so it’s important to take a “big picture” look at how the systems work together and affect each other when diagnosing.
What can I do to diagnose and repair a P0104 engine code?
If you need to replace the MAF sensor, we recommend using an original equipment OEM one from the manufacturer rather than buying an aftermarket part.
Note: The use of a reusable oiled air filter could be a cause of this code if it is over-oiled. Oil can transfer to the fine wire or film inside the MAF sensor and contaminate it. In such situations, use something like MAF cleaner spray to clean the MAF. We do not recommend the use of oiled air filters.
