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P0101 OBD Error Code: Problem & Solutions

OBD Code P0101 - Mass or Volume Air Flow Circuit Range/Performance

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Oftentimes, Engine Warning Light turns up almost immediately it senses the OBD code error. This directly impacts the engine performance as it struggles with power and acceleration as well as failed fuel system causing increased consumption of fuel by the engine.


OBD-II Code P0101 is defined as a Mass Air Flow Sensor Circuit Range/Performance Malfunction

Learn More About OBD Code P0101

When the engine is running, air passes through the MAF (Mass Air Flow) sensor, which sends a voltage signal to the engine controller. Depending on how much air is passing through the sensor, the voltage varies. The ECU (Engine Control Unit) measures the MAF signal to be within a certain range, depending on RPM and load. If the MAF signal goes outside of this range, higher or lower voltage than expected, the ECU ignores it and sets an OBD Code P0101 Error.


What causes the problem of Mass Air Flow Sensor Circuit/Performance Malfunction?


  • Faulty, dirty or obstructed mass air flow sensor (MAF)
  • Intake boot (snorkel) cracked, ripped or disconnected
  • Vacuum leaks (from stuck open PCV valve, leaking intake gaskets, etc.)
  • Improperly installed or clogged air filter
  • Excess oil from an oil-soaked air filter in the MAF sensor element
  • Clogged up catalytic converter or restricted exhaust Dirty throttle body
  • Faulty or dirty manifold absolute pressure (MAP) sensor
  • Electrical problems with the wiring and connectors to the MAF sensor
  • EGR valve stuck open
  • Affected valve timing
  • Faulty Powertrain Control Module (PCM)

Replace/Repair These Parts To Fix OBD Code P0101

  1. Mass Air Flow Sensor - If the sensor is unable to measure the air flow pressure correctly, it will hamper the air intake system and fuel delivery system. Replace faulty sensors immediately.
  2. Air Filters - Check for clogged and damaged air filters and replace them if found so. Buy new air filters form us.
  3. Diagnostic Tool - Always use a professional factory grade OBD scanning and testing tools to diagnose the OBD errors. Buy quality tools from us now!
  4. Engine Control Module - OBD Error Code P0101 can also be due to faulty EVMs. It’s better to get the faulty electricals replaced as soon as possible. Replace faulty ECM today!
  5. Powertrain Control Module - P0101 error code also relates to problems with the powertrain that can cause engine performance issues. Find all the Powertrain related parts with us.
  6. Catalytic Converter - Excessive amounts of unburned gas caused by a misfiring spark plug or a leaky exhaust valve can cause overheating of catalytic converter. Replace your old catalytic converter now!
  7. Manifold Absolute Pressure Sensor - Problematic MAP sensor can cause excessive fuel consumption, lack of power, and increased emission from the exhaust. Thus, replace faulty sensors now!
  8. Intake Valve - Burnt valve can cause increased fuel consumption, affected engine performance, rough idles and engine stalling and not starting. Thus, replace damaged valves immediately.
  9. PCV Valve - Faulty PCV valve can cause increased internal engine pressure, failure of oil seals and gaskets, engine oil leaks and much more. Thus, it is important to replace them, if found faulty.
  10. Manifold Gasket Set - Damaged intake gasket can cause engine misfires with affected power, acceleration and fuel economy. Thus, replace them now!
  11. Throttle Body - Symptoms of bad or failing throttle body include poor engine performance, stalling, and broken electrical connections. Thus, resolve this issue immediately. 

Symptoms Of OBD Error Code P0101

Following are the symptoms indicating OBD code P0101:


Common Symptoms


  • Check Engine Light On
  • Engine running rough and stalling
  • Smoke emitting from exhaust tail pipe
  • Lack of power on acceleration
  • Engine hard starting

How To Correct P0101 Mass or Volume Air Flow Circuit Range/Performance

The most common potential repairs to address the P0101 code are as follows:


  • Verify the code with an OBD-II scanner. Reset the fault codes and perform a road test using a live data scanner.
  • If the P0101 code flashes back, then follow the test procedure prescribed for that code.
  • Check for electrical connector to insure it is securely attached. Disconnect it and then reinstall to insure fresh and clean electrical connection. Insure no high voltage sources are near the MAF or its wiring.
  • Visually inspect for wiring being frayed or broken on the connector. Repair or replace, if found faulty.
  • Inspect for vacuum leaks on the intake, especially on older cars which can have cracks due to age of the materials.


At Parts Avatar Canada, find best replacement and performance parts for repairs related to any OBD error for any make and model. Explore now!

Easy Diagnosis Of Engine Error OBD Code P0101

The first step is to check for Technical Service Bulletins (TSBs) that apply to your year/make/model/engine, and then do a visual inspection of the wiring and system components. Also take help of an experienced mechanic who used professional diagnostic tools to diagnose this problem. Also, it is important to follow the diagnostic steps properly to avoid any misdiagnosis and stopping the P0101 code from returning again. Following are the steps to be followed:


  • 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.
  • Check for any obvious air leaks in the air intake system
  • Inspect the MAF sensor wires or film to see contaminations such as dirt, dust, oil, etc.
  • Carefully clean the MAF and air intake mesh.
  • Loss of vacuum to the MAP sensor can trigger this DTC. A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leaks downstream of the MAF sensor.
  • Monitor real-time sensor values from the MAF sensor, O2 sensors, etc. using a scan tool.
  • The barometric pressure (BARO) that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON.
  • A high resistance on the ground circuit of the MAP sensor can cause this DTC to set.
  • Do an exhaust back pressure test to determine if the catalytic converter may be clogged.


Common mistakes when diagnosing the P0101 code


By far, the most common cause of a P0101 being stored is a disconnected MAF sensor. When the air filter is checked or replaced, the MAF sensor is often left disconnected. If your vehicle has recently been service, and a code P0101 is suddenly stored, suspect that the MAF sensor has simply been left unplugged.


Some of the common mistakes done while changing diagnosing the OBD code P0101 are:


  • Intake manifold leakages
  • Mass Air Flow (MAF) sensor failure/faulty
  • Powertrain Control Module (PCM) failure
  • Wiring and Connection issue

Other Diagnostic Codes Related To OBD Code P0101

P0100 - Mass or Volume Air Flow "A" Circuit Malfunction

P0102 - Mass or Volume Air Flow "A" Circuit Low Input

P0103 - Mass or Volume Air Flow "A" Circuit High Input

P0104 - Mass or Volume Air Flow "A" Circuit Intermittent