The Powertrain Control Module (PCM) regulates the amount of air pressure in the exhaust manifold, through the use of a switching valve, which protects the Secondary Air Injection System pump. In order to achieve this goal, a group of sensors is included in this system that sends reference signals to the PCM about the existing air pressures.
When the switching valve is open, the PCM takes an accurate reading of the pressures in the SAI system compared to those provided by the manufacturer to verify proper system operation. If these pressures differ widely from those stored in the Powertrain Control Module’s memory, it will interpret this as a stuck closed or faulty switching valve condition, which will store the P2441 OBDII diagnostic code.