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P0340 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.

Definition

A P0340 code indicates a camshaft position sensor circuit malfunction. Basically, the computer has sent a signal to the camshaft position sensor, but it does not see the right signal that is being returned from the sensor.

Because the circuit is a concern, the problem could be in any component of the circuit such as in the Power Control Module, the wiring, or the sensor itself.

Meaning

The camshaft position sensor calculates the rotational speed of the camshaft and where the camshaft is positioned in that rotation. The camshaft sensor then sends a signal to the Power Control Module (PCM) to communicate this information. The PCM then uses the information collected by the camshaft position sensor to set the fuel injector timing and control the ignition spark.

When the signal to and from the camshaft position sensor and the PCM is broken, the ignition spark and fuel injector timing will fail and the PCM will store the P0340. This will trigger the illumination of the Check Engine Light.

Causes

There are several potential causes behind a P0340 code. One cause could be that a camshaft position sensor circuit wiring is broken, shorted, or corroded. Or, a camshaft position sensor circuit connector is broken, shorted, or corroded.

If that is not the case, then you may have a faulty camshaft position sensor, or a failed crankshaft position sensor. Lastly, you may have a faulty PCM.

Symptoms

There are a few symptoms you should look for when diagnosing a P0340. Either the check engine light will come on, or the vehicle may not start, or will be difficult to start.

The vehicle also may idle or stall, or could misfire. Lastly, there could be a loss of power while driving.

Diagnosis

To verify the problem, use an OBD-II scanner to retrieve all of the trouble codes that have been stored by the PCM. Then, inspect the camshaft position sensor wiring for wires that are broken, corroded, or shorted. Inspect the camshaft position sensor connector for connectors that have broken or corroded.

Once you have all of that completed, inspect the camshaft position sensor circuit wiring for wires that are broken, corroded, or shorted. Check the continuity of the camshaft position sensor circuitry. Then, complete any necessary repairs for other related trouble codes that have been stored by the PCM.

Use a scan tool or oscilloscope to check the camshaft position sensor voltage readings,

If the voltage readings are abnormal, the camshaft position sensor will need to be replaced.

If the voltage readings for the camshaft position sensor voltage readings are normal, it is possible that there is a problem with the PCM, which may require replacing or reprogramming.

Common mistakes

There are a few ways that correcting a P0340 can go wrong. Before replacing the camshaft position sensor, it is important to inspect the wiring and connectors to rule them out as the cause of the problem. This is the most common mistake when diagnosing the P0340 trouble code.

Another mistake that is made during the diagnostic procedure is neglecting to consider a misfiring problem or a crankshaft sensor problem as possible sources of the P0340 trouble code.

How serious is this?

This code is considered serious. The car may not start or be difficult to start. While operating the vehicle, the driver may also experience a lack of power. These symptoms make the operation of the vehicle dangerous for the driver and anyone else on the road.

It is also possible for damage to be caused to other components in the engine if the P0340 trouble code goes unaddressed for an extended period of time. The P0340 trouble code should be diagnosed and repaired immediately.

What repairs can fix the code?

Thankfully, there are a few repairs that can fix code P0340. You can repair or replace the camshaft position sensor circuit wiring, or repair or replace the camshaft position sensor circuit connector.

If those repairs don’t work, you may need to replace the camshaft position sensor or the crankshaft position sensor.

 If misfire codes are present, you should perform a tune-up of the vehicle before replacing the camshaft position sensor. You can also try replacing or reprogramming the PCM.


Related codes

Some related codes are P0341, P0342, and P0343.

Conclusion

The P0430 code is not something that can be ignored. If left untreated, it can cause serious damage to your vehicle.

Thankfully, there are some effective diagnostic steps that can determine the source of the problem, and there are some repairs that can fix the problem entirely. You should attempt the repair options right away to eliminate the code and fix your vehicle. If you try all of these methods and the problem persists, there may be something more seriously wrong with your vehicle that is beyond code P0340.