P0103: Air flow sensor circuit high input
The ECU sees a voltage that is too high on the air flow sensor signal. Usually a wiring problem, a poor earth or the sensor itself.
| Code | P0103 |
|---|---|
| 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 P0103 means
The air flow sensor sends a signal that rises with the air coming in. If the ECU sees it above what is possible, it stores this code. It is normally electrical: a loose earth, a signal wire touching a live feed, or a failed sensor sending maximum all the time.
Most common causes
- Corrosion or moisture in the sensor connector
- Loose or poor sensor earth
- Chafed signal wire touching a live wire
- A faulty air flow sensor
- Interference from an ignition lead or a badly fitted accessory nearby
Symptoms
- Engine warning light on
- Engine running rich: higher consumption and black smoke on diesels
- Rough idle or jerking
- Loss of power
Can you drive with P0103?
With care You can drive, but the engine may use more fuel and foul the catalytic converter or particulate filter. Get it fixed soon.
How to check it
With the ignition on and the engine off, air flow in live data should read zero or close to it. If it already shows a high figure with no air moving, the fault is in the sensor or its wiring.
How to read and clear P0103 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 P0103 with this same explanation and whether it’s confirmed, pending or permanent.
With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.
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 the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.
Similar codes
- P0100 Mass or volume air flow sensor circuit fault
- P0101 Air flow sensor range or performance problem
- P0102 Air flow sensor circuit low 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
- P0110 Intake air temperature sensor circuit fault
- P0111 Intake air temperature sensor range or performance
P0103 is a generic code, so it means the same on any make, for example on Audi, Fiat, Mazda, Peugeot, Toyota, Volkswagen. See what Final OBD does on your car in makes and models.
What does code P0103 mean?
The air flow sensor sends a signal that rises with the air coming in. If the ECU sees it above what is possible, it stores this code. It is normally electrical: a loose earth, a signal wire touching a live feed, or a failed sensor sending maximum all the time.
Can you drive with P0103?
You can drive, but the engine may use more fuel and foul the catalytic converter or particulate filter. Get it fixed soon.
How do you clear P0103?
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, P0103 comes back.
Read it on your car
Final OBD reads the faults of every control unit for free, including each make’s own codes, and with Pro explains each one in plain English. Free clears engine faults at no cost.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com