P0101
Mass or volume air flow "A" circuit range/performance
The ECU has detected a mass-air-flow reading that is outside the expected operating range.
What this code means
The ECU has detected a mass-air-flow reading that is outside the expected operating range.
Possible causes
- Dirty or contaminated mass air flow sensor
- Air leak or vacuum leak in the intake system
- Damaged MAF wiring or connector
- Restricted or contaminated air filter
- Faulty MAF sensor
Common symptoms
- Check engine light
- Rough idle or hesitation
- Reduced power
- Poor fuel economy
- Possible black exhaust smoke
Checks to make
- Check for other stored diagnostic trouble codes
- Inspect the intake pipework for splits or loose connections
- Inspect the air filter
- Inspect the MAF connector and wiring
- Use live data to compare MAF readings with expected engine operation
Safety
- Avoid touching the sensing element inside a MAF sensor. Follow vehicle manufacturer procedures before disconnecting electrical components.
Model notes
Exact diagnostic thresholds and repair procedures vary by vehicle manufacturer.