The CMP sensor (Camshaft Position Sensor) is an electronic piece that records the speed at which the camshaft rotates. The information obtained by this sensor is sent to the ECM (Engine Control Module). The ECM uses it to manage the fuel injection and ignition.
The Camshaft Position Sensor detects the retraction of the camshaft (intake) to recognize a determined cylinder and detect the position of the piston. Typically, this kind of sensor is composed of a disk and the actual sensor. Once the engine is started, both the lower and upper parts of the teeth cause variations in the gap with the sensor. This change consequently causes the magnetic field near the sensor to change as well, affecting the sensor voltage.
In most cases, the P1340 OBDII fault code is a specific code that indicates that the Camshaft Position Sensor has experienced erratic operation. Consult your vehicle manufacturer’s source of information for its application.