Bad Camshaft Position Sensor Symptoms and Replacement Cost

Bad Camshaft Position Sensor Symptoms

The role that the Camshaft Position (CMP) sensor plays in the engine of a vehicle includes gathering information regarding the camshaft speed of a vehicle and sending it to the Engine Control Module (ECM). The ECM then utilizes the data in determining the actual ignition timing and the timing of fuel injection required by the engine. In the absence of this data, the engine may not be able to function properly, thus seeing some bad camshaft position sensor symptoms.

Through time, this camshaft position sensor will become worn down, even failing. This could be a result of natural wear and tear, as well as accidents. While this could cause some problems, there are some warning signs or symptoms that you can observe before this part of the engine fails completely, shutting down the engine. I have seen a lot of vehicle owners acting late on this, making a replacement of the camshaft position ( CMP ) sensor a necessity in the end.


7 Bad Camshaft Position Sensor Symptoms

1. Illumination of the Check Engine Light

One of the bad camshaft symptoms that you may notice includes the lighting of the “Check Engine” alert on the dashboard. However, you need to know that alert could also indicate other problems, and may not just only mean a bad camshaft position (CMP) sensor.

When this happens, you may then proceed to use an OBD2 scan tool in order to get the stored diagnostic trouble codes in the vehicle. A better way is to ask the professional assistance of a technician in inspecting the ECM of the vehicle and see what the problem is. This module is scanned to get a series of error codes, which could indicate what the problem is.

It is often not good to ignore this alert, or simply postpone the inspection of the vehicle, as this could only result in serious problems. The engine may fail, which means that you may have to replace or rebuild the engine completely. 

Try to understand the P0345 CODE: Camshaft Position Sensor Circuit Malfunction Bank 2

2. Stalling Engine

When there is a camshaft position sensor problem, another symptom that you may see is that the engine stalls or shuts off while you are driving. This is possible because the fuel injectors are not being alerted to inject fuel right to the cylinders of the engines. This could be a very dangerous situation when unfixed.

3. Problems in Ignition

As the vehicle’s camshaft position sensor begins to show weakness or problems, the signal that is transmitted to the computer of the car also weakens. This only means that the signal will eventually become weak that it will no longer allow your car to start because there will no longer be a spark that happens upon ignition.

4. Vehicle Surging or Jerking

When driving your car and then there is a problem with your camshaft position sensor, the car engine will simply lose power at times, causing your car to surge or jerk, or just surge forward randomly. These could be a result of an inaccurate amount of fuel that is injected right into the cylinders because the PCM receives incorrect information coming from the camshaft position sensor.

5. Issues with Shifting

Some car models that encounter faulty CMP sensors will only deal with a locked transmission, which becomes stuck in a specific gear. In order to deal with it, and as a temporary fix for the crankshaft position sensor, it is to shut the engine off, wait for a bit, and restart. Still, this is just a temporary fix, which means that the problem will still appear again. When that happens, a replacement camshaft position sensor may be required for a permanent fix. Aside from this, your car may also place it into the “limp mode”, not allowing you to accelerate above a given speed or even to shift gears.

6. Bad Fuel Mileage

A bad fuel mileage often comes as a result of an inaccuracy in the reading of the camshaft position sensor. Because of the fault, more fuel than what is actually needed is injected right into the engine, thus causing the fuel economy of the vehicle to drop significantly.

7. Poor Acceleration Capabilities

Aside from the issues mentioned earlier involving jerking and stalling, you may also notice that your car will not be able to accelerate as needed. In fact, in some cases, it may not be possible to accelerate beyond the 30 mph target in certain cases. This could be a result of the incorrect delivery of fuel, as instructed by the injectors.


Camshaft Position Sensor Replacement Cost

To replace the camshaft position CMP sensor of your vehicle, the expected cost is anywhere between $120 and $300. The parts may cost you between the range of $50 and $200. On top of that, you can also expect the labor cost to play in the range of $70 to $100.

Of course, you may also have to expect to pay a bit extra if you own a luxury vehicle, or if a local car dealer will do the replacement. Added to the cost to be expected are extra fees, as well as taxes that are involved in the service. Having a camshaft position sensor replaced early at the onset of the problem may be cheaper than having it at a more serious stage. 


Last Words

The symptoms mentioned above will not only introduce a disappointing inconvenience on your part. It could also be dangerous, especially when the symptoms happen when you are driving. When you notice that your vehicle is no longer running like it used to, it may be best to have the camshaft position sensor checked. 

True, replacing the cam position sensor can be done by yourself, but having a professional look into a problem will do a thorough job. This is also applicable if you do not know how to check for bad camshaft position sensor symptoms. If you are noticing a problem, such as an early alert from the Check Engine Light, contact us to look into the problem and perform the necessary repairs.


About the Author JamesL Davis

James is a certified auto technician specializing in commercial vehicles. With 30 years of experience under his belt, James has encountered almost every type of automotive issue there is! Besides his day job at the repair shop, he is also an amateur race car driver.

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