Fault-Code Library · Air metering
P0101: Mass-air-flow signal range / performance
Airflow reported by the MAF sensor does not agree with the ECU's calculated operating conditions.
Common symptoms
- •Poor response
- •Smoke
- •Uneven idle
- •Fuel-economy change
Likely causes
- •Air leak after the sensor
- •Contaminated or failed MAF
- •EGR flow problem
- •Boost or intake restriction
First checks
- •Inspect intake hoses and clamps
- •Compare MAF data with expected values
- •Check EGR and boost plausibility before replacing the sensor
Important
A MAF code often describes a system plausibility problem, not automatically a failed MAF sensor.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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