DTC P0340: Camshaft Position Sensor - Circuit Malfunction: Description

The Camshaft Position (CMP) sensor located on rear of cylinder head (side towards transmission) consists of a signal generator (photo transistors) and signal rotor (slits plate). The CMP sensor generates reference and position signals through 2 types of slits in silt plate which turns with camshaft. The 2 signals are as follows:

1. Reference Signal
   
   During one full camshaft rotation, CMP sensor generates 4 signal pulses, each of which has a different waveform length. Based on CMP sensor reference signal, ECM is able to determine which cylinder is in compression stroke.
2. Position Signal
   
   During one full camshaft rotation, CMP sensor generates 360 signal pulses (one pulse equals one degree of camshaft rotation). Based on CMP sensor position signal, ECM is able to determine engine speed and piston position.