P0104 Mass Air Flow MAF Circuit Intermittent
Description and meaning of DTC p0104
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles that have a mass airflow sensor. Brands include but are not limited to Ford, Mercedes, Peugeot, Toyota, Honda, Citroen, Nissan, VW, Jeep, Chevrolet, Dodge, etc. Although generic, the specific repair steps may vary depending on make/model. The MAF (mass air flow) sensor is a sensor mounted in a vehicle's engine air intake tract downstream from the air filter, and is used to measure the volume and density of air being drawn into the engine. The MAF sensor itself only measures a portion of the air entering and that value is used to calculate the total volume and density of air being ingested. The powertrain control module (PCM) uses that reading along with other sensor parameters to ensure proper fuel delivery at any given time for optimum power and fuel efficiency. This P0104 diagnostic trouble code (DTC) means 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 signalis not performing within the normal expected range of the calculated MAF value. Note: Some MAF sensors also incorporate an air temperature sensor, which is another value used by the PCM for optimal engine operation. Closely related MAF circuit trouble codes include P0100, P0101, P0102, and P0103.
p0104 diagnostic trouble code symptoms
Symptoms of a P0104 code may include:Malfunction indicator lamp (MIL) illumination (a. k. a. check engine light)Rough running engineBlack smoke from tail pipeStallingEngine hard start or stalling after it startsPossible other driveability symptoms or even no symptoms
DTC p0104 - possible causes
Potential causes for this trouble code may include:Dirty or contaminated mass air flow sensorFailed MAF sensorIntake air leaksMAF sensor electrical harness or wiring problem (open, shorted, frayed, poor connection, etc. )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 effect each other when doing a diagnosis.
How to fix OBD-II diagnostic trouble code p0104
Visually inspect all MAF sensor wiring and connectors to make sure they are intact, not frayed, broken, routed too close to ignition wires/coils, relays, motors, etc. Visually inspect for any obvious air leaks in the air intake systemVisually *closely* inspect the MAF sensor wires or film to see if you can see contamination such as dirt, dust, oil, etc. If the air filter is dirty, replace it with a new original equipment filter from the dealerCarefully clean the MAF using MAF cleaner spray is generally a good DIY friendly diagnostic/repair stepIf the air intake system has a mesh in it, make sure that is also clean (VWs mainly)Loss of vacuum to the MAP sensor can trigger this DTCA low minimum air rate through the sensor bore may cause this DTC to setat idle or during deceleration. Inspect for any vacuum leaks downstreamof the MAF sensor. Use a scan tool to monitor real-time sensor values from the MAF sensor, O2 sensors, etc. Check for Technical Service Bulletins (TSBs) for your particular make/model in case of known issues on your vehicle The barometric pressure (BARO) that is used in order to calculate the predictedMAF value is initially based on the MAP sensorat key ON. A high resistance on the ground circuit of the MAPsensor can cause this DTC to setIf you do 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. Use something such as MAF cleaner spray to clean the MAF in such situations. We do not recommend the use of oiled air filters.