Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
The DTC P0340 Camshaft Position (CMP) sensor circuit diagnostic monitors the signal from CMP sensor. CMP sensor is a magnetic generator type sensor that produces an AC signal. CMP sensor signal increases in frequency as engine RPM increases. CMP signal is used by Powertrain Control Module (PCM) to determine optimum ignition timing and optimum fuel delivery. CMP sensor is also used to monitor engine misfire and monitor operation of CMP actuator system.