Error Code P0102: Mass Air Flow (MAF) Circuit Low Input

Error code P0102 means the mass air flow sensor had lower than expected voltage input.

Definition

In vehicles with electric fuel injection systems, the mass airflow (MAF) sensor determines the flow-rate of air going into the engine through the intake valve. The engine control unit (ECU) interprets the information and determines how much fuel should be delivered to the engine. This is an important component of electronic fuel injected engines.

The P0102 code is the code for a problem with the Mass Airflow (MAF) Sensor. It gives off a low voltage output to the Engine Control Unit. In order for the ECU to function properly, the MFA flow rate must be within a preset range of values and if the MFA communicates a number too low, the ECU won’t function effectively. The vehicle will run rough.

The MFA and oxygen sensors work closely together to communicate to the ECU the correct amount of airflow that allows the engine to work properly. With the information from the sensors, the ECU passes the information on to the automobile’s computer. The amount of fuel flow is then calculated and applied. The process is repeated every cycle. If everything works right, the engine runs well. The error code P0102 occurs when the breakdown in communication between the MAF sensor and the ECU results in poor performance in the vehicle. The problem isn’t always easy to detect.

Common Symptoms

  • Check Engine Light Comes On
  • Loss of Power
  • Sluggish Drive
  • Poor Fuel Consumption
  • Idles Rough
  • Overall Poor Engine Performance If Not Fixed

Possible Causes

  • The airflow from the air filter may be clogged The MAF sensor may have become disconnected
  • The wiring may be worn out or broken
  • The MAF sensor may be plugged
  • The screen may be dirty
  • The MAF sensor may be broken
  • The proximity of the sensor to electrical parts like wires or the field poles of an alternator can cause poor performance of the MAF sensor
  • The vehicle computer may be malfunctioning (check this as a last resort)

How to Check

The “Check Engine” light comes on, indicating a problem. Plug your scanner into the car’s computer, and read the error code. If the reader shows P0102 then that means the ECU has generated the error code and the error is in the MAF sensor. The code points to low fuel consumption in the system, calling for a repair.

How to Fix

First, drive the car around to reset the code. Plug the scanner in again and see if it recurs. If so, a flaw in the MAF sensor must be fixed or the MAF must be replaced. Check for loose parts, frayed wires or broken components. Inspect for vacuum leaks. The MAF unit can be removed and cleaned, using recommended cleaning fluids like an aerosol brake parts cleaner. Check for the correct voltage for the MAF sensor. If all else fails, remove and replace the MAF sensor.

Parting Tips

Once the problem is identified and fixed, clear and reset the codes again and drive the car some distance. Check the scanner again to see if it fixes the problem or the code recurs.

 

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