P0340 - Camshaft Position Sensor 'A' Circuit Malfunction


Error Code P0340 is a very common fault code. Your vehicles computers such as ECM, PCM and many more used the CMP or also known as camshaft position sensor to easily figure out what it should set the timing at. This is an important tool, since without knowing what the right timing should be the computer is useless.

The error code P0340 simply means that the computer has completely sent a signal to the camshaft position sensor however it does not see the right signal that is being returned from the sensor. Since the circuit is a concern, the problem could be in any component of the circuit such as PCM, wiring and sensor itself.

What causes the code?


  • Faulty Camshaft Position Sensor 
  • Camshaft Position Sensor harness is open or shorted 
  • Camshaft Position Sensor circuit poor electrical connection 
  • Faulty starter motor 
  • Starting system circuit Dead (Weak) battery


Fault Code Related Video 


Tech notes 

Sometimes and in some models, low battery voltage or a weak starter can trigger a Camshaft Position Sensor code. 

When is the code detected? 

The camshaft position sensor signal is not detected by the Engine Control Module(ECM) during the first few seconds of engine cranking 



Description 

The Camshaft Position Sensor is an electronic device used in an engine to record the rate at which the camshaft is spinning. This information is used by the Engine Control Module(ECM) to control ignition and fuel injection. The camshaft position sensor senses the retraction of camshaft (intake) to identify a particular cylinder. The camshaft position sensor senses the piston position. The sensor system consists of a rotating part, typically a disc, as well as a static part, the actual sensor. When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change. The changing gap causes the magnetic field near the sensor to change. The change in the magnetic field cause the voltage from the sensor to change. When the crankshaft position sensor (POS) system becomes inoperative, the camshaft position sensor provides various controls of engine parts instead, utilizing timing of cylinder identification signals.