P0340 code – Causes, information & Fix

The P0340 OBD II code is used to identify a problem in the vehicle’s camshaft position sensor. In this article, we are going to look at what causes the camshaft sensor to fail and how to fix it when it does.

Error code P0340 is one of the most common problems in a car. It is the problem associated with the camshaft sensor. The camshaft position sensor (CPS) is part of the huge fuel system in cars.

When the internal combustion engine is running, fuel and air have to mix for ignition and this is where the camshaft sensors come in. The engine requires perfect timing of the fuel and air mixture during ignition and the camshaft sensors are responsible for this timing.

Wrong timing means the vehicle is going to experience misfires. For this correct timing to be achieved, the sensors work hand in hand with the onboard computer to determine the right timing.

This means that if the sensor is faulty or missing, the onboard computer is useless since it has been receiving wrong signals. Wrong timing leads to problems such as loss of vehicle power and difficulty in starting the car. These cause the engine light on the dash to come on.

The camshaft position sensor also records the rotation rate of the camshaft and sends this information to the onboard computer – the PCM.  The PCM uses this information to control the amount of gas and air mixing and the ignition timing. This is how engines are able to ignite and power up.

What does P0340 mean?

The Camshaft Position Sensor is found in the internal combustion engine. It regulates and monitors the rotational speed of the camshaft. This information is then taken to the onboard computer or power control module and the computer then controls timing of the injectors and spark plugs.

When error code P0340 is read, it means that the fuel injector and the ignition spark plugs timings have failed. The code is triggered by the breakage of signal between the onboard vehicle computer and the camshaft sensors.

The engine then misfires since it does not know when to fire these components. It is important to remember that the code does not indicate exactly where the root problem is, it only indicates where the larger problem is. You will need a mechanic to look at your engine to find the exact root problem and fix it.

Can I drive with the P0340 error code?

The short answer to this question is yes. However, depending on the extent of damage and how soon you discovered the problem, the answer could vary. This error code indicates a faulty camshaft position sensor.

When you have a P0340, the engine is likely to stall as you drive. This means that you will not be able to comfortably ride in your car until you get the issue fixed.

Symptoms of P0340 code

The symptoms for this error code can be as simple as the engine light coming on. They could also be quite severe depending on the extent of damage.

Other than the engine light on the dash coming on, there are a few symptoms that can help you identify a camshaft issue. They include the following.

Rough Idling

Rough idling is when the car shakes or vibrates intensely when idling, or when the car is stopped but the engine is still running. When the car does this, it could indicate a P0340 error code. However, this symptom is common for most engine problems and can be inaccurate when trying to figure out if the problem is a P0340.

Reduced engine power

When there is a P0340 error code, you will notice that the engine’s vehicle is weak. Acceleration is much slower and the engine seems to be struggling where it never did. In extreme cases, the engine can stall and the car stops.

Stalling

Stalling is when the vehicle suddenly stops when you were driving. Stalling is usually accompanied by intense rough vibrations and engine misfires in extreme cases. When the car suddenly starts stalling, it could mean that the camshaft sensors are faulty.

Engine misfires

If you’ve ever heard a loud gunshot-like sound from the exhaust, this is what is referred to as a misfire. A misfire occurs generally when there is a serious problem in the engine or one of its components. A P0340 error code can easily cause a misfire if the fuel and air mixture are of wrong ratios and timings.

Difficulty in starting the car

When you turn on the ignition and find that it is hard and rigid to start, there is a high chance you have a P0340 error code.

If the camshaft problem is intermittent, there is a high chance you will not experience any of these physical symptoms. Only the engine light comes on in this situation.

It is important to identify problems early enough at the intermittent stage and repair them. This will be way cheaper as components are not badly damaged. Intermittent stage is the early stages of the problem that usually indicated a permanent problem is coming.

How to diagnose and fix a P0340 error code

Once the OBD II scanner reveals a P0340 error code, you should get it fixed immediately before it grows into a much serious and expensive problem. The following are ways to find exactly where the problem is and how to fix it.

Check the wires and wiring

For communication to take place between the camshaft sensors and the onboard computer, there has to be a connection. This connection is a bunch of intricate wires interconnected together.

If any of these wires is loose or broken, communication between these two components is lost. You should first check the battery wiring to ensure the terminals are tightly connected.

You should then check the ground wire between the engine and vehicle’s body. Finally, check the wires from the sensors to the PCM for any visible breakages or damages, and check whether they are tight enough.

Check the camshaft sensors

When a P0340 error code is found, there is a high chance that the problem is a broken camshaft sensor. In fact, in many cases, this is usually the problem.

If the camshaft position sensors are damaged or have accumulated dirt and debris over time, they will not work. Find the sensors and visually inspect them. Replace the broken ones and clean the dirty sensors to get the car going again.

Check the fuses

As we know, any electric component in a car has a fuse to control the amount of electric current entering the circuit. If the fuses to the camshaft are damaged or melted, you will get P0340 error code. Check to make sure the fuses are in good condition and if not, replace them

Check the camshaft reluctor

This is rarely the problem but should be checked as well to eliminate the possibility. Visually inspect the reluctor wheel found on the camshaft. The reluctor wheel is where the camshaft reads all the information from. If you have already replaced the sensors and wires, check the wheel to ensure they are fine too.

Conclusion

If you have a faulty camshaft position sensor, it is important that you fix it immediately to prevent further engine damage. It will be way cheaper as components are not severly damaged.