The energy generated by the engine or exhaust pulses is used in a forced induction system to achieve an increase in the amount of air that can be introduced. In these systems, the intake pressures change and need to be adjusted to the different power requirements. For this reason, manufacturers use a boost control valve, which monitors and controls the Engine Control Module (ECM) to check that the air-fuel mixture is suitable.
The P00AF OBDII fault code is set when the ECM finds a performance problem in the operation of the Boost Control Module A.