P02E9: Diesel Intake Air Flow A Position Sensor Circuit High — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
A high electrical signal is reported for the diesel intake-airflow A position-sensor circuit. A high sensor signal must not be confused with an excessive physical intake-airflow condition.
Affected system: Powertrain
Symptoms
- The engine warning lamp may illuminate, with possible sluggish acceleration or unstable idle.
- Some vehicles may show no obvious drivability symptoms beyond the stored fault.
Possible causes
- Damaged, disconnected or corroded wiring and terminals at the diesel intake-airflow position sensor.
- A faulty intake-airflow position sensor; an engine controller fault is a less common possibility.
What to check
- Record associated fault codes, then visually inspect the sensor connector and harness for loose pins, corrosion or damaged insulation.
- Check the sensor circuit with a meter against the vehicle-specific service procedure before considering replacement.
Also written as: P02E9-00, P02E900, PO2E9 (some scan tools add the fault-type byte, e.g. -00).