7 Symptoms of a Bad Camshaft Position Sensor (and Replacement Cost)

The Camshaft Position sensor is a crucial electrical component in your vehicle. It helps gather information about the vehicle’s camshaft speed and then sends it to ECM (Engine Control Module). Here, the ECM determines the fuel injection timing and timing of the actual ignition of the engine. Without this data, the engine won’t function properly, and it will result in bad camshaft position sensor symptoms.

With time, the camshaft position sensor will wear down due to accidents or natural wear and tear. However, you can look out for some symptoms or warning signs of the bad camshaft position sensor.

In this article, we will understand what a camshaft position sensor is and the symptoms of a bad camshaft position sensor. Lastly, we will discuss the replacement cost to expect when you have a faulty camshaft position sensor.

What is a Camshaft Position Sensor?

A Camshaft Position Sensor is crucial for your vehicle as it ensures whether the engine is functioning properly or not. Different car manufacturers use different places to mount the sensor near the engine. You can find it close to the engine block, vehicle’s lifter valley, or at the back of the cylinder head.

Problems caused by a Faulty Camshaft Position Sensor

A faulty camshaft position sensor can induce a number of problems depending on the car model and the failure.

  • A bad camshaft position sensor can result in locking transmission in a single gear. To unlock, you need to turn off and start the engine again.
  • There will be a significant loss of power such that your engine stalls and will suffer poor acceleration below 35 miles per hour.
  • A bad camshaft position sensor results in car jerking while moving and losing excessive power.
  • You will also notice the poor performance of the engine, such as misfiring, surging, or hard starting.

Reasons for the Failure of Camshaft Position Sensors

As mentioned above, camshaft position sensors fail due to mechanical damage, accidents, or wear and tear. Furthermore, the camshaft position sensor is susceptible to heat, vibration, and contamination in the engine.


Excessive heat can result in a bad camshaft position sensor. Heat causes the sensor’s metallic parts to expand in the engine compartment. The expansion impairs the ability of a sensor to send the correct input to the car’s computer.


The car’s engine tends to produce vibration when it is operating. However, the camshaft position sensor is designed to handle those vibrations, but excessive vibrations can put excessive pressure on the engine. Also, it will fluctuate the engine and lead to improper fuel/air mixtures and faulty timings.

Corrosion and Contamination

You will generally find the camshaft position sensor on the cylinder head of the engine. The gaskets and broken seals will leak the coolant and oil inside the sensor. Just like other electronic devices, rust, oil, and water will weaken the functioning of the sensor.

7 Symptoms of a Bad Camshaft Position Sensor

How to find that your camshaft position sensor isn’t functioning properly? You need to look out for the camshaft position sensor symptoms or warning signs so that you can replace a bad camshaft position sensor at the earliest.

Ignition Problems

When your vehicle has a bad camshaft position sensor, the signal transmitted to the car s computer weakens. When the signals are weak, your car will not start as there is no spark from the ignition system.

Check Engine Light Illuminates

If your car’s dashboard shows “Check Engine Light,” that means your camshaft position sensor has started having issues. However, the check engine light could also mean other problems, not necessarily indicates a bad camshaft position sensor.

To check if there is a problem with your camshaft sensor, you either contact the professional mechanic or use an OBD2 scan tool. Both will scan the control module of the vehicle engine to receive error codes from check engine light. The error codes will explain the cause of the problem.

Whenever the Check Engine light comes, do not delay checking the engine as it can lead to more damage. It could also result in a total fall down of the engine.

Car Surging or Jerking

If there is a bad camshaft position sensor, it will lead to jerking or surging of the car. That means your car will lose its power while driving.

While this could also be due to inaccurate fuel injection into the cylinder as PCM received the wrong information due to a faulty camshaft.

Poor Acceleration

In addition to the car surging or jerking, you will also notice the poor acceleration of the car. In most cases, your car won’t be able to accelerate above 30 miles per hour. That is because of incorrect fuel delivery by fuel injectors.

Engine Stalling

Shutting down and stalling the engine is another symptom that you will encounter while driving the car. Due to the bad camshaft position sensor, the fuel injectors are not ordered to inject fuel into the engine cylinder.

The situation can become quite dangerous if not addressed on time. Most of the time, the engine of the car can go in the Limp mode because of faulty camshaft position sensors.

Issues with Shifting the Gears

The bad camshaft position sensors can result in locked transmission, making your car stuck in a single gear. The temporary fix is to shut down the engine and wait for some time before restarting.

The problem will occur again because it was a temporary solution. For a permanent fix, you need to replace the camshaft position sensor. Just like the engine stalling problem, the car will go into limp mode and will not accelerate above a specific speed to change the gears.

Bad Fuel Mileage

A bad camshaft position sensor leads to high fuel consumption and lower power. In such situations, the camshaft position sensors provide inaccurate readings because of which more fuel has been injected that causes a drop in the fuel economy.

Camshaft Position Sensor Replacement Cost

The average camshaft position sensor replacement cost is somewhere around $100-$250. The labor cost is between $30-$130, while the auto parts will cost you around $75 to $125.

The prices will vary due to certain factors such as your location, your supplier, or the company with which you are dealing. For a luxury car, the camshaft sensor replacement cost can be higher. It can cost you additional charges between $30 and $130. However, if you can get your sensor replaced by yourself, the cost will be reduced to half the price.

Is it Possible to Replace the Camshaft Position Sensor on your own?

Yes, you can replace the bad camshaft position sensor by yourself. This is one such job that doesn’t need professional help and where you can save the labor cost. It would take about five to ten minutes to replace the bad camshaft position sensor.

Though replacement from a dealer or repair shop will guarantee reliability, they will charge you a minimum of $100 for their service. If you want to save money, you can do it yourself by taking help from the service manual or videos.

Testing the Bad Camshaft Position Sensor

To test the bad camshaft position sensor, you will require a multimeter tester. The latest models of a car come with either Hall-effect or magnetic-type camshaft position sensor. You will test the sensor while the ignition is on and later when the engine is operating.

For testing the Hall-effect sensor, connect the ground wire with the black multimeter probe. After that, connect the sensor’s signal wire with the red probe. The device voltage should be within the specified voltage of the manufacturer. Lower voltages mean the sensor is damaged.

The same goes with the magnetic sensor; here, you will connect the black probe of the multimeter with ground point such as engine bolts, cylinder head cover, etc., and then connect the signal wires with the red probe. If the voltage is either lower or higher than specified, the sensor is not working properly.

Replacing A Bad Camshaft Position Sensor

If you are having difficulty replacing and install the new camshaft position sensor, you can follow the below-mentioned steps or refer to the service manual.

  • First, make sure that all the negative battery cables are disconnected.
  • Locate the position of the sensor that is situated ideally on the rear part, front, or top of the engine. You will find two-three wires attached to it.
  • Disconnect the wires by releasing the tab situated on the camshaft position sensor. It is a typical 10mm or 8 mm bolt.
  • With a slight twist, pull off the sensor.
  • On the O-ring of the new camshaft position sensor, apply a small amount of engine oil.
  • Install and secure the new camshaft position sensor with the help of the mounting bolt.
  • Attach the wire connector will the new camshaft position sensor and then the negative battery terminal.

Final Thoughts

The symptoms of a bad camshaft position sensor will not only cause inconvenience but is also dangerous if they occur while driving. At any given time, you notice that the car is not running efficiently; you should get your camshaft position sensor checked.

You can either do the replacement by yourself or take help from a professional. First, look out for the major problems and alerts like the check engine light to avoid any issues later on.

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