Mass or Volume Air Flow Circuit Range/Performance
The mass air flow (MAF) sensor measures the air going into the engine; the engine computer uses it to work out how much fuel to inject. This code means the value it sends doesn't match what the engine computer expects for the current engine speed and load.
What the car has detected
The MAF signal is outside the believable range for the engine's state (it is not a cut signal, but a value that doesn't fit the rest of the data).
You can drive, but the engine may lack power or run with the wrong mixture, and in the long run use more fuel or foul the catalytic converter. Get it checked soon.
Symptoms
- Engine warning light on
- Lack of power
- Higher fuel consumption
- Rough idle, hesitation or stalling
- Hard starting
- Black smoke from the exhaust
Possible causes
- Dirty or worn MAF sensor (on some diesels it gets dirty over the years and loses accuracy)
- Air leak between the MAF sensor and the engine (air that isn't measured)
- Restricted airflow: dirty air filter, blocked screen or clogged exhaust
- Corroded or faulty MAF wiring, connector or earth points
- Mechanical loss of engine performance that makes the reading not add up
Checks for the garage
- Check the MAF wiring, connector and earth points
- Check the air filter and intake for restrictions
- Look for leaks between the MAF sensor and the engine (on turbo engines, also before the turbo)
- Compare the MAF reading in live data with the expected values at idle and when revving
- Clean the MAF sensor with a dedicated cleaner without touching the element and replace it if it doesn't improve
Next step
Check the air filter and that there are no loose hoses between the MAF sensor and the engine; if it continues, have the sensor and its connector checked.
Go to a garage if the filter and intake are fine and the code comes back, or if the car loses a lot of power. Checking the MAF signal needs diagnostic equipment.