P0101
Airflow sensor reading doesn't match what the engine computer expects for the throttle opening
Severity: Inspect soonAir metering (MAF, MAP and intake air temperature) codes
The engine computer needs to know how much air the engine is taking in to calculate how much fuel to inject. Most engines measure it with a mass airflow (MAF) sensor, some infer it from manifold pressure (MAP) and intake air temperature. If those readings are wrong, the fuel calculation is wrong too.
How these codes differ
- P0102 (MAF low input) and P0113 (intake air temperature sensor high input) are circuit-type codes: the signal is outside what the sensor can physically produce, which points to wiring, connectors or the sensor's electronics.
- P0101 (MAF range or performance) and P0106 (MAP range or performance) mean the signal is plausible electrically but does not agree with what the computer expects from other readings such as throttle position and engine speed. That points toward contamination, an air leak around the sensor, or a sensor that has drifted.
- Because airflow feeds the fuel calculation, an airflow fault often shows up first as a fuel trim code, and fixing the airflow problem is what clears both.
Codes that show up together
- P0101 with P0171 and P0174: a MAF that under-reads air makes both banks run lean, so the MAF is the shared lead.
- P0113 with P0102 when the intake air temperature sensor is built into the MAF housing: a shared connector or wiring fault is a likely common cause.
Air metering (MAF, MAP and intake air temperature) codes
P0102
The airflow sensor's signal is lower than the engine computer will accept
Severity: Inspect soonP0113
The intake air temperature signal is stuck at a reading colder than any real air could be
Severity: MonitorP0106
Manifold pressure (MAP) sensor reading doesn't match what the engine computer expects
Severity: Inspect soonP1101
On GM and GM-era Saab engines, the airflow worked out from throttle position doesn't match the airflow measured by the MAF and MAP sensors
Severity: Inspect soonP0108
The manifold pressure (MAP) sensor is sending a voltage that stays too high for the engine load
Severity: MonitorP0100
Mass or volume air flow sensor circuit fault
Severity: MonitorP0107
Manifold pressure or barometric pressure sensor signal too low
Severity: MonitorP0097
Intake air temperature sensor 2 circuit signal too low
Severity: Inspect soonP0103
The mass airflow sensor is reporting a signal that stays too high
Severity: MonitorP0104
The mass airflow sensor signal drops out or comes and goes
Severity: MonitorP0105
Manifold pressure / barometric pressure sensor signal is abnormal
Severity: Inspect soonP0111
The intake air temperature reading does not agree with what other sensors suggest
Severity: MonitorP0112
The intake air temperature sensor signal reads too low in voltage, which the computer interprets as extremely hot intake air
Severity: Severity not verifiedP0114
The intake air temperature signal comes and goes
Severity: MonitorP0129
Barometric pressure reading lower than the engine computer expects
Severity: Severity not verifiedP2074
The computer sees the intake manifold pressure and throttle position disagree in a way that points to too much air or a vacuum leak
Severity: Severity not verifiedP2227
The engine computer sees a barometric pressure reading that does not fit the engine load and throttle opening
Severity: Inspect soon
Sources and review
- Final Regulation Order: 13 CCR §1968.2, Malfunction and Diagnostic System Requirements (OBD II), 2004 and subsequent model-year passenger cars, light-duty trucks and medium-duty vehicles (2015 amendments)
- Protect your MAF sensor with a clean air filter
- Lean On Me
- Ford P0171 & P0174 Lean Codes (Larry Carley)
- Service Slants: GM Inline Engine Cam Actuator Solenoid
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error