In forced induction systems, it is necessary to vary and adjust the intake pressures according to power requirements. For this reason, manufacturers use a direct boost control valve or solenoid that is directly controlled by the Engine Control Module. The ECM checks that the air-fuel mixture is appropriate. To achieve this, it adjusts the vanes on the charger, which regulates the amount of boost into the chamber.
The DTC P003A OBDII code is set when the ECM detects that the position of the booster control arm “A” is not within the range allowed by the manufacturer.