P0103 OBD-II Trouble Code: Mass Air Flow (MAF) Circuit High Air Flow and High Output Voltage
OBD2 Error Codes

P0103 OBD-II Trouble Code: Mass Air Flow (MAF) Circuit High Air Flow and High Output Voltage

14.09.2023 /

P0103 - What does the trouble code mean?

Mass Air Flow (MAF) Circuit High Air Flow and High Output Voltage

The Mass Air Flow (MAF) sensor is located inside the intake air flow and is designed to measure the air intake speed. This sensor involves a hot film that receives electrical current from the Engine Control Module (ECM). The hot film temperature is controlled by the ECM to a certain extent. As the intake air passes through the sensor, the heat generated by the hot film is reduced. The more air is sucked in, the more heat is lost. Therefore, the ECM regulates electrical current to maintain hot film temperature as air flow changes. This process allows the ECM to determine airflow based on changes in electrical current.

The P0103 code is often associated with the closely related P0100, P0101, P0102, and P0104 codes.

What does code P0103 mean?

P0103 is a problem code for the Mass Air Flow (MAF) sensor with high voltage output from the Engine Control Unit (ECU).

P0103 OBD-II malfunction code

P0103 – causes

Increased voltage at the output of the mass air flow sensor to the ECU can have several sources:

  1. It is possible that the sensor output voltage is higher than normal, or the ECU requires higher signals from other sensors to operate.
  2. The wiring or the MAF sensor itself may be placed too close to higher voltage consuming components such as alternators, ignition wires, etc. This may result in distorted output signals.
  3. There may also be an air flow leak in the intake system, starting from the air filter assembly and ending in front of the mass air flow sensor itself. This could be due to a faulty intake hose, air intake, loose hose clamps, or other leaks.

Mass airflow sensors must operate within certain limits to provide the ECU with accurate signals to properly configure and work with other sensors to ensure proper engine operation.

Possible Causes P0103

  1. The mass air flow sensor is faulty.
  2. Air leak in intake.
  3. The mass air flow sensor is dirty.
  4. Dirty air filter.
  5. The MAF sensor harness is open or shorted.
  6. Problems with the mass air flow sensor circuit, including a poor electrical connection.

Symptoms of code P0103

The P0103 code is usually accompanied by the Check Engine light turning on on your instrument panel.

In general, the car is still capable of driving, but its performance may be a little unstable. The engine often performs acceptably, but sometimes some problems appear, such as rough running, decreased power, and longer idling times than usual.

If the engine shows serious problems, immediate action must be taken to avoid possible damage to the engine.

Before replacing the MAF sensor, try replacing the air filter and cleaning the MAF sensor using a low level compressed air cleaner or MAF sensor cleaner. Reset the code and drive the car. If the code returns, the MAF sensor may need to be replaced. What does it mean?

How a Mechanic Diagnoses Code P0103

Error P0103 is diagnosed using an OBD-II scanner. Once the OBD-II code has been cleared, it is recommended that you test drive the vehicle to see if the error occurs again and the light comes on again. You can observe this by monitoring the scanner while driving. If the code returns, the mechanic will have to do a thorough visual inspection to determine if any components need to be repaired or replaced, such as electrical connectors, wires, sensors, air filters, intake or intake hoses, as well as check for loose clamps and the condition of the MAF .

If the visual inspection reveals no problems, the next step is to test the circuit using a digital display multimeter. This will allow you to measure the sampling rate and read the sensor readings to determine if the MAF sensor output is indeed too high.

Common Mistakes When Diagnosing Code P0103

Often diagnostic errors are associated with incorrect execution of the following steps:

  1. First, perform a test procedure to check the connector, wiring, and the MAF sensor itself. You should not immediately buy a new MAF sensor if other tests do not reveal any problems.
  2. Before you decide to purchase a new MAF sensor, try cleaning it using an aerosol cleaner specifically designed for MAF sensors, such as CRC 05110. These sensors often accumulate carbon from the emissions system, especially at idle.
  3. Note: Simple causes of air intake system problems may include loose clamps, air hoses, or vacuum lines. Therefore, before purchasing an expensive MAF unit, you should carefully check and inspect the intake system.

How serious is code P0103?

The P0103 code usually does not prevent your vehicle from driving unless the leak is severe. However, to prevent possible problems, it is recommended that you contact a qualified technician and have it checked as soon as possible.

Problems with the MAF sensor can cause excessive fuel consumption, smoke, rough engine operation, and difficult starting in certain situations. Continued operation of the vehicle in this condition may cause damage to internal engine components.

Often, if the check engine light comes on immediately after starting, the OBD-II system can be reset and the vehicle may temporarily operate normally. But it is still recommended to diagnose and solve the problem in order to avoid possible consequences.

What repairs will help eliminate code P0103

There are several common methods to repair code P0103:

  1. Start by double checking the code using a scanner. Clear fault codes and perform a road test.
  2. If code P0103 returns, follow the test procedure sequence.
  3. Inspect the electrical connector to make sure it is properly connected. Unplug it and then reinstall it to ensure a good electrical connection.
  4. Carefully check any worn, damaged or broken connector connections. Make repairs or replacements as necessary before continuing testing.
  5. Check for vacuum leaks, loose hoses, and defective fittings and clamps in the intake system, especially on older vehicles. Components that are older may become more fragile and prone to breakage.
Causes and Fixes P0103 Code: Mass or Volume Air Flow "A" Circuit High

P0103 Brand specific information

Many vehicles with high mileage exceeding 100 miles may temporarily experience sensor problems, which most often occur when the engine is started or during times of intense stress on the transmission.

If the check engine light is flashing but the car is running normally, the OBD-II system can be reset using a scanner and the problem may not reoccur. Therefore, it is important to check the error and reset it before starting any repairs.

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