DTC P0340: Camshaft Position Sensor Circuit Malfunction: Condition

WARNING: This page is about a different car, the 2002 Mazda Protege5 and 2002 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.

DTC is set when there is no input from Camshaft Position (CMP) sensor with Mass Airflow (MAF) sensor reading more than 2.2 gram/sec. This is a continuous monitor. MIL is illuminated when PCM detects malfunction during first drive cycle. Possible causes are:

CMP sensor malfunction.
CMP sensor dirty.
Short or open circuit between CMP and PCM.
CMP reluctor wheel malfunction.