How Camshaft sensor Affects Engine Performance | Bad camshaft position sensor symptoms

Posted by HJL_ADMIN 1 on

The Engine Will Not Start

Have your car shuts off while you’re driving?

As a camshaft position sensor weakens, the ECM (Engine Control Module) switches off fuel and spark delivery that can be a dangerous situation. If you ignore the symptoms which your camshaft position sensor fails, or any other listed here, eventually your engine will not start.


Then, what are the symptoms of a bad or failing camshaft position sensor that you need to know?


Common Symptoms of a bad camshaft position sensor


The followings are the camshaft position sensor symptoms:

-Engine Stalling

-Check Engine Light Comes On

-Poor Drivability

-Transmission Shifting Problems

-Bad Fuel Economy 

- Engine Idles Roughly

-Smell of Gas


These are the signs that a car problem can be found before it gets serious. Although your car won't fail immediately if the camshaft position sensor has a problem. But your vehicle's overall performance will degrade over time. These symptoms may appear together or separately. Normally, the check engine light will come on in conjunction with one or more symptoms. Since the camshaft has an important role, when it is not good, it will also cause many problems.

So you might be wondering, what is a camshaft position sensor?

Why is it so important?

What is a camshaft position sensor? 

How does it work?

The camshaft position sensor location is near the camshaft, usually on top of or around the valve cover. This is an electronic device that helps a vehicle's computer get the maximum performance out of the engine. The main function is to monitor the camshaft position upon speed and provides the data to the vehicle's ECM (Engine Control Module) which in return to use this information to deliver engine power.

These parts work together to ensure the right amount of fuel and air to the combustion chamber and ensure the engine works at the right moment.


So if the camshaft position sensor is not working properly, it will cause your car to have problems to start, to accelerate or to stall, so on and so on. That's why it is one of the important parts of the car engine.


(If you can add more features of a camshaft sensor, please comments below to share with us)


What causes a camshaft sensor to go bad?


There are numerous reasons that cause a camshaft position sensor to go bad. The main causes may be a damaged timing belt, bad wiring, overheating, crank walks, etc.
Some of these also include wear-and-tear, water damage, and oil embedded in the engine, these can also damage the engine's camshaft since these things will build up over time.


If there’s a problem, the engine control module and associated wiring may need to be replaced. It may even be necessary to replace the camshaft position sensor. While it is not uncommon for camshaft sensors to fail completely and sometimes that could be related to other engine parts. The easiest way is to prevent dirt build-up, make sure the engine is cleaned regularly, and also check the sensors at least once a year when you get your car serviced.



P0340 Error Code

Very first step to deal with any CEL on situation is to plug on the diagnose tool to see the faulty codes.

If the check engine light comes on. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.

For example, the P0340 is a faulty code for "Camshaft Position Sensor Circuit Malfunction". It could be the wires leading to the camshaft sensor fail, or the sensor itself has a fault.


P0340 Causes

The reasons to trigger P0340 faulty code could be,
- A damaged camshaft/crankshaft position sensor

- ECM (Engine Control Module) failure

- ECM (Engine Control Module) software update required

- Damaged or dirty reluctance ring on the camshaft

- Poor wiring, corrosion, short circuit of camshaft position sensor circuit

- Damaged, corroded, shorted camshaft position sensor circuit connector

- Stretched or misaligned timing components


How to fix the P0340 code?

After figuring out the cause of the faulty camshaft position sensor, we recommend to find a professional repair shop nearby to pinpoint the problem.

According to mechanic recommendations to fix the following:

- Replace the camshaft/crankshaft position sensor

- Repair or replace camshaft position sensor circuit or connector

- If a misfire code comes on, tune up the vehicle before replacing the camshaft position sensor.

- Replace or reprogram the PCM (Powertrain Control Module).


Driving with a Bad Camshaft position sensor

Let’s say now you have the feeling that your camshaft sensor is failing.

Although the camshaft position sensor is small, it is very important to your car's engine. Your car can also stall when a camshaft sensor fails. This can be dangerous for you, your passengers and everyone on the road. Be sure to thoroughly check the system before making any decisions. It's best to take your car to a professional mechanic right away and let them fix the problem.



Replacing the Camshaft position sensor is a good way to fix the camshaft position sensor symptoms.

If you experience the signs of a faulty camshaft position sensor, please addressing the problem immediately that can prevent additional failures and higher service cost.


As for the Camshaft position sensor repair costs, generally speaking, it is  an average of $160 to $240 including labor costs.

Following any other auto parts replacement, the cost is varied by the model, the year of car; as well as the cost of individual repair shop.


We hope this reading can help you a lot.
If you like it, please kindly share! More information and content are in HJL Autoparts. Thanks for reading!


Read more:


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