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P0103 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

P0103 is an OBD-II Code that refers to Mass or Volume Air Flow Circuit High

Meaning

A P0103 code is caused by an ECM (Engine Control Module) receiving a signal that the MAF or Volume Air Flow Sensor is showing a High flow or volume of air. The ECM will use this information to determine how much fuel to inject into the engine for proper running. If the signal is not within the ECM’s programmed or expected parameters for certain periods of time, it will set a P0103 code.

Causes

Common causes for this code include:

  • MAF Sensor is disconnected, or it has failed
  • Air filter is dirty or clogged
  • Vacuum leaks
  • Circuit or harness is open or shorted

Also read: 6 Easy Steps On How To Clean A Car Air Filter

Symptoms

The symptoms of a P0103 code are:

  • MIL (Malfunction Indicator Lamp) will illuminate
  • Vehicle may be difficult to start
  • Rough idle
  • May stall
  • Black smoke is emitted from exhaust

Diagnosis

To diagnose a P0103 DTC code, a technician would:

  1. Check the MIL (Malfunction indicator Lamp) – If it is turned on, check to see if there are any stored codes and record them.
  2. Check harness connectors for signs of damage or corrosion and repair as necessary
  3. Check for leaks in the intake or vacuum system
  4. Check sensor resistance to both power and ground
  5. Check all wiring circuits for shorts, opens, and damage
  6. Repair / Replace
  7. Test Drive

Common mistakes

The following are some of the most common mistakes that a technician may make when diagnosing a P0103 code:

  • Not checking for stored DTCs
  • Not checking all of the harness connectors
  • Not checking sensor resistance to both power and ground
  • Not looking for leaks in vacuum hoses or intake system
  • Not testing wiring circuits for shorts, opens, or damage
  • Clearing codes without diagnosis

How serious is this?

A P0103 code is serious and can cause poor running conditions if ignored. The MIL (Malfunction Indicator Lamp) will remain on until the code is cleared, meaning it is constantly affecting vehicle performance. Each vehicle manufacturer has its own set of actions it may take when presented with a P0103 or any other DTC that could potentially affect drivability or emissions.

What repairs can fix the code?

Repair manualsRepair manuals

The following are solutions that may fix this problem:

  • Replacing the MAF Sensor
  • Replacing the air filter
  • Checking or replacing vacuum hoses or components
  • Cleaning the sensors and components for dust, grime or dirt
  • Replacing wiring, connectors, and grounds
  • Replacing the ECM (Engine Control Module) Rare

Related codes

A P0103 is related to and may be accompanied by the following codes:

P0100P0102, P0103, P0106 – OBD II generic codes that refer to fuel and air metering

P0105 – Mass or Volume Air Flow Circuit Range/Performance

Conclusion

In conclusion, the P0103 code is a generic trouble code that means the computer has detected an issue with the Mass or Volume Air Flow and it’s Circuit is sending a High signal which means that there is an issue with the sensor’s operation or related components. When this code appears, it is serious and can cause poor running conditions if ignored. Each vehicle manufacturer has its own set of actions it may take when presented with a P0103 or any other DTC that could potentially affect drivability or emissions.