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.


The CPS is an electronic device that is usually utilized in an engine to easily and quickly record the rate at which the camshaft is spinning. This information is basically used by ECM (also known as the Engine Control Module) that has the ability to control fuel injection and ignition. In addition to this, the camshaft position has the ability to sense the piston position. Apart from this, the sensor system consists of actual sensor, static part and rotating part. Once the engine is running, the low and high parts of the teeth cause the gap with the sensor to change. This is one of the reasons why the changing gap causes the magnetic field near the sensor to change. In this way, the magnetic field can cause the voltage from the sensor to change. When the crankshaft position sensor becomes inoperative, the camshaft position sensor provides different controls of the engine parts with the use of timing of cylinder identification signals.

Common Symptoms

Symptoms include the following:

  • Loss of engine power
  • Misfiring or rough running
  • No start or hard starting
  • Engine stall
  • Engine light ON or service engine soon warning light

Possible Causes

The error code P0340 most likely means that one or more of the following has happened:

  • A connector or wire in the route circuit could be broken, shorted or grounded.
  • Faulty PCM
  • Open circuit
  • Faulty crankshaft position sensor
  • Dead or weak battery
  • Starting system circuit
  • Faulty starter motor
  • Poor electrical connection of the camshaft position sensor
  • The harness of the camshaft position sensor is shorted or open
  • Faulty camshaft position sensor

How to Check?

With the help and existence of error code P0340, you can be sure that diagnosis can be easily performed. Here are some of the effective things that you should try to perform:

  • The first thing that you need to do is to visually examine all the connectors and wiring in the route circuit
  • Check for stability in circuit wiring
  • Verify the operation or voltage of camshaft position sensor
  • Replace the camshaft position sensor when needed
  • Check the crankshaft position circuit
  • Replace the circuit wiring or connectors when needed
  • Replace or diagnose the PCM as required

 How to Fix?

In order for you to properly and successfully fix an error code P0340, the first thing that you should do is to check all the wiring. Here are the important steps that you need to follow:

  • Make sure that the battery cable connections are tight and clean. Some people think that it is an obvious step, but if your computer does not get a steady feed of electricity from the battery, it can cause multiple issues.
  • Check for wires and connectors that might be rubbed through, disconnected or loose. It is also important to check the fuse box in your vehicle together with the relay center that can be found under the hood.
  • It is also important to make sure that the fuses are good. Make sure that there is no melted plastic that can cause fire. These are some of the major wiring problems that you will encounter with error code P0340.
  • Once you have completely checked all the obvious things and still you can’t find the right solution, then you have to begin suspecting either the computer or the sensor.
  • The camshaft position sensor is defective. Unfortunately, there is no way for you to test it since it will take expensive test and equipment as well as well trained and fully skilled technician to the test the sensor.
  • You can also consider the CMP sensor and install it. This will greatly help you to fix the problem however there is no guarantee without proper diagnosis.