The ECM (Engine Control Module) monitors and adjusts the sensors that operate the vehicle. Besides, it detects faults within the system and circuits.
One of the systems monitored by the ECM is the intake manifold adjustment valve. This valve contributes to engine performance and driveability. Besides, it regulates the pressure between the intake gaskets, redirects air into intake channels, and changes engine flow and performance.
Diagnostic code P0661 OBDII indicates that the ECM has found an excessively low electrical reading on the intake valve in bank number 1. This code is activated due to mechanical or electrical failure. Especially if the valve is in an area of extreme cold exposure, the valve may malfunction.