P0101: Air flow sensor range or performance problem
The air flow sensor measures an amount of air that does not match what the ECU expects. Usually a dirty sensor or an air leak.
| Code | P0101 |
|---|---|
| System | Engine and transmission |
| Group | P01xx, Air and fuel metering |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P0101 means
The air flow sensor signal arrives, but the ECU compares it with what should be entering the engine based on revs, throttle and other sensors, and it does not match. Most often the sensor is dirty or air is getting in somewhere without passing through it.
Most common causes
- Very dirty or badly fitted air filter
- Air leak between the sensor and the engine (split hose or loose clip)
- Dirty sensing element (dust, or oil from oiled air filters)
- Cracked or loose vacuum hose
- The air flow sensor itself ageing or faulty
- On turbo engines, a leak in the turbo or intercooler hoses
Symptoms
- Loss of power or jerking
- Rough idle
- Higher fuel consumption
- Black smoke on diesels
- Engine warning light on
Can you drive with P0101?
With care You can drive, but the engine may feel flat, use more fuel and in the long run clog the catalytic converter or particulate filter. Get it checked.
Open the bonnetthe in-depth explanation
How to check it
In live data, read air flow at idle with the engine warm, then rev it gently in neutral: the figure should rise smoothly. Also check by eye that every hose between the air filter and the engine is secure.
How to read and clear P0101 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0101 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P0100 Mass or volume air flow sensor circuit fault
- P0102 Air flow sensor circuit low input
- P0103 Air flow sensor circuit high input
- P0104 Air flow sensor circuit intermittent
- P0105 Manifold absolute pressure (MAP) sensor circuit fault
- P0106 Manifold absolute pressure (MAP) sensor range or performance
- P0107 Manifold absolute pressure (MAP) sensor circuit low
- P0108 Manifold absolute pressure (MAP) sensor circuit high
- P0109 Manifold absolute pressure (MAP) sensor circuit intermittent
What does code P0101 mean?
The air flow sensor signal arrives, but the ECU compares it with what should be entering the engine based on revs, throttle and other sensors, and it does not match. Most often the sensor is dirty or air is getting in somewhere without passing through it.
Can you drive with P0101?
You can drive, but the engine may feel flat, use more fuel and in the long run clog the catalytic converter or particulate filter. Get it checked.
How do you clear P0101?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P0101 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
