P0103: Mass or Volume Air Flow Sensor A Circuit High. Meaning, possible symptoms and checks before repair.
Meaning, symptoms, causes and checks
The controller finds the MAF A input above its permitted electrical range. This does not by itself prove excessive actual airflow. Outputs may use voltage, frequency or digital data, so test the installed sensor type.
Affected system: Powertrain
Symptoms
- Engine warning light; a fallback operating mode is possible.
- Uneven idle, hesitation or reduced power, depending on the control strategy.
Possible causes
- Signal shorted to supply or an internal MAF failure.
- Contaminated connector or damaged wiring; check the intake configuration.
What to check
- Record RPM, load and MAF at the time of storage; determine whether the fault is current or intermittent.
- Inspect the connector, wiring route, MAF installation and intake-duct sealing without touching the sensitive element.
- Measure supply and ground using the diagram; do not assume every MAF uses the same supply voltage.
- If the input stays very high, check shorts to supply and compare the module input with the actual sensor output.
- After repair, clear codes and recheck the MAF input under the original recorded conditions, following the manufacturer’s procedure.
Also written as: P0103-00, P010300, PO103 (some scan tools add the fault-type byte, e.g. -00).