P0101 – Meaning, Causes, Symptoms, & Fixes
Code P0101 Definition
Mass Air Flow (MAF) Circuit/Performance Malfunction
Code P0101 Meaning
The mass air flow (MAF) sensor measures the amount of air entering the engine. Check engine light code P0101 is set when the measurement of air entering the engine by the mass air flow sensor is outside of the manufacturer’s specified range.
Symptoms of Code P0101
- Engine stalling
- Difficulty starting
- Lack of power
- Rough idle
Causes of Code P0101
- Dirty, obstructed, or faulty mass air flow sensor
- Damaged or disconnected air intake boot (snorkel)
- Vacuum leak
- Clogged or improperly installed air filter
- Clogged catalytic converter / restricted exhaust
Code P0101 Severity – Moderate
Code P0101 does not pose any danger to the driver and will not prevent the vehicle from running. However, it will cause an increase in fuel consumption and rough operation. Sustained driving can lead to internal engine failure.
Code P0101 Common Diagnosis Mistakes
Buying and installing a new mass air flow sensor without completing the entire diagnosis process.
Code P0101 Diagnosis Steps
- Tools Needed to Diagnose:
How To Diagnose P0101
- Locate your air intake box that houses your air filter. Open the air intake box using the required tools for your vehicle. Ensure the air filter is seated properly and is clean. Reseat the air filter if it is not seated properly, and replace the air filter if it is dirty. This may be as much as you need to fix P0101, however, we recommend completing step 2 as well. It is not difficult or expensive, and may improve performance.
- Remove the wiring harness from the mass air flow sensor and remove the air intake snorkel from the air intake box. Use mass air flow sensor cleaner (DO NOT SUBSTITUTE FOR ANY OTHER KIND OF CLEANER) to clean out the MAF sensor. Do this by spraying each side of the MAF sensor for 3-5 seconds, waiting 10 seconds, and then spraying it again for 3-5 seconds. Do not wipe it. The MAF sensor hot wires are very sensitive, and MAF sensor cleaner cleans and dries very quickly. Reconnect the air intake snorkel, close the air intake box, and reconnect the MAF sensor harness. Clear the check engine light code using the FIXD app and complete several drive cycles to ensure this was the correct fix. Here is a great video to show you this process!
- If your check engine light comes back on with diagnostic trouble code P0101, examine the air intake system for vacuum leaks.
- If no vacuum leaks are found, it is likely a restriction in your exhaust.