Bad Camshaft Position Sensor Symptoms, Causes, and Replacement Cost

The engine relies on the crankshaft and camshaft working harmoniously, with the camshaft position sensor ensuring precise timing. Identifying a bad camshaft position sensor involves recognizing its impact on engine performance.

Symptoms Of Bad Camshaft Position Sensor

However, the data of both the crankshaft position sensor and the camshaft position sensor play a vital role in ensuring efficient performance. Issues with either can disrupt the overall performance of your vehicle.

Notably, the camshaft sensor remains active when your engine runs. As a result, wear and tear over time, along with other factors like cracks, oil leaks, or engine overheating, may lead to its malfunction. This article describes the bad camshaft position sensor symptoms, replacement cost, and how to test it.

Function of a Camshaft Position Sensor

The camshaft position sensor serves as an electronic component that gauges the position and rotational speed of the camshaft. This information is then transmitted to the engine control module (ECM) of the car. The ECM utilizes the input of the camshaft sensor to precisely time the delivery of spark and fuel, optimizing overall engine performance.

Camshaft Position Sensor function

Accurate ignition timing leads to decreased exhaust emissions, improved fuel efficiency, and improved engine power.

In the case of the latest engine designs, the camshaft position sensor takes on the role of identifying the specific cylinder in its power stroke compared to the position of the crankshaft. This determination enables the sensor to facilitate the provision of precise spark and fuel when you press the accelerator pedal, initiating engine ignition.

Typically attached to the engine and equipped with an electrical connection, camshaft sensors are both compact and paramount. Their magnetic functionality underscores their significance in the engine’s functioning.

Symptoms Of A Bad Camshaft Position Sensor

The check engine light illumination or hard engine starting condition is one of the most common symptoms of a bad camshaft position. However, a bad camshaft sensor may also lead to a misfiring engine, poor engine performance, rough idle, stalling engine, or increased emissions.

A complete list of different signs of a bad camshaft position sensor is given below:

1) Check Engine Light Illumination

Check Engine Light

When the camshaft sensor becomes faulty, your vehicle’s main computer may trigger the check engine light. Often, the singular symptom indicative of a faulty camshaft position sensor is the activation of the check engine light on the dashboard.

When the check engine light starts to illuminate on your car’s dashboard, it’s advisable to seek the expertise of an automotive specialist who can conduct a scan of your vehicle’s systems to identify any associated trouble codes.

Alternatively, this diagnostic process can be carried out using an OBD-II scan tool at home. Unfortunately, many individuals overlook the illuminated check engine light, unaware that it could signify a potentially serious concern, possibly even resulting in engine damage.

2) Vehicle Won’t Start

Car Won’t Start, symptoms of bad camshaft position sensor

If your engine is hard to start or won’t start at all, it is one of the clear signs of a bad camshaft position sensor. As the camshaft sensor becomes faulty, it fails to transmit the necessary signal to your vehicle’s ECM. Consequently, the ignition system’s ability to generate an accurate spark is compromised.

When the spark is missing, the engine won’t start, showing that the camshaft sensor might be broken. In modern vehicles, advanced systems have the ability to sense faulty camshaft position sensors and, in response, shift reliance to the crankshaft position sensor as an alternative measure.

Read More: Reasons Why Your Car Won’t Start?

3) Reduced Engine Performance

Poor Engine Performance

A reduction in engine performance is also one of the most common symptoms of a bad camshaft position sensor. This decline becomes evident through diminished engine speed, unstable idling, and frequent stalling. Furthermore, a decrease in fuel economy becomes apparent. 

These issues warrant prompt attention, often stemming from a faulty camshaft sensor. Such problems are commonly linked to the possibility of the engine entering Limp mode due to the sensor’s malfunction.

4) Poor Transmission Shifting

Transmission Shifting Issues, signs of bad camshaft sensor

Vehicles equipped with an automatic transmission can encounter gear-shifting issues when affected by a malfunctioning camshaft position sensor. In such cases, the solution often involves turning off the engine, allowing a brief interval to pass, and then restarting.

Furthermore, when the ECM of your vehicle receives wrong information from the faulty camshaft position sensor, it might impede the operation of the shift solenoid responsible for gear changes.

Read More: Bad Shift Solenoid Symptoms and Causes

5) Engine Misfire


A faulty camshaft sensor may lead to engine misfires. This, in turn, may result in vibrations during driving. If you perceive a noticeable decline in your car engine’s performance alongside the illumination of the check engine light, it’s undoubtedly a prudent time to investigate the vehicle’s trouble codes.

6) Poor Fuel Economy

Poor Fuel Economy

A reduction in engine power resulting from a faulty camshaft sensor may also contribute to poor fuel economy. While this doesn’t happen often, it’s still possible. When you observe an unusually high fuel consumption pattern, it’s advisable to scrutinize the vehicle’s trouble codes, particularly those linked to the camshaft position sensor.

7) Fuel Smell

When the camshaft sensor isn’t working properly, it can cause unburned fuel to get into the exhaust system of your car. This can affect how efficiently your fuel is used and even make black smoke come out of the exhaust pipe, which is annoying. Also, this unburned fuel may create a clear smell that’s not safe for the car’s passengers.

8) Engine Stalling

Engine Stalling

Among the most concerning scenarios within your engine is stalling—an occurrence where the engine abruptly halts while you’re driving. This issue arises when the fuel injectors fail to supply the necessary fuel to the combustion chamber. Primarily, a malfunctioning camshaft position sensor is often responsible for this inadequate fuel supply.

As the fuel injector doesn’t deliver the appropriate amount of fuel, the result can be engine stalling, an issue that can potentially lead to costly repairs.

9) Rough Idling

Rough Idle, symptoms of bad camshaft position sensor

A malfunctioning camshaft position sensor can lead to rough idling in the engine. This happens because a faulty sensor can disrupt the proper timing of ignition inside the cylinders.

However, rough idling can also be caused by other factors like a faulty idle fuel valve, a clogged throttle body, or a faulty EGR valve.

Read More: Rough Idle Causes and Fixes

10) Failed Emissions Test

Failed Emission Test

A bad camshaft position sensor may also lead to the emission test failure. When the engine doesn’t operate properly, it might struggle to burn the air-fuel mixture properly, which can lead to increased emissions. This could cause your vehicle to fail an emission test.

11) Jerking During Acceleration

Jerks during acceleration can be caused due to a bad camshaft position sensor. When your ECM tries to regulate the fuel and ignition timing correctly based on the wrong camshaft position information, it may lead to jerking conditions.

Read More: Why Your Car Jerk While Driving

Causes of a Bad Camshaft Position Sensor

The camshaft position sensor becomes faulty due to one or more of the following causes:

  • Normal wear and tear
  • Electrical issues
  • Oil leaks or improper sealing
  • Physical damage
  • Exposure to extreme heat
  • Poor installation
  • Manufacturing faults
  • Excessive vibrations or shocks
  • Environmental factors, such as exposure to moisture or corrosive substances

Camshaft Position Sensor Location

Camshaft Position Sensor Location

Where the camshaft position sensor is positioned depends on the engine’s model and design. However, the camshaft position sensor is usually installed near the camshaft. Frequently, it’s on the top of the valve cover, but it may also be on the cylinder head’s side.

If you look around the valve cover or cylinder head and follow the wiring, you can easily locate the camshaft position sensor. It is recommended to consult your owner’s manual to find the location of the camshaft position sensor for your vehicle.

Camshaft Position Sensor Replacement Cost

The replacement cost of the camshaft position sensor fluctuates based on factors such as the supplier, your location, and the manufacturer. The average replacement cost of the camshaft position sensor ranges from $80 to $280. The sensor itself is priced around $60 to $140, while labor costs can be between $20 and $140.

Conducting a bit of market research can aid in securing the most favorable prices for both the sensor and related labor costs.

On average, changing a camshaft sensor doesn’t usually break the bank, averaging between $60 and $140 for most models. It’s worth noting that luxury cars might sustain higher replacement costs.

How To Test Camshaft Position Sensor

FAQ Section

Can I drive with a faulty camshaft position sensor?

While it’s possible to drive with a faulty camshaft position sensor, it’s not advisable. A malfunctioning sensor can lead to poor engine performance and even prevent your car from starting. Although it’s unlikely to cause your car to abruptly shut off, but driving in this condition is discouraged. Replacing the bad camshaft sensor promptly is the recommended course of action.

Does a new camshaft sensor need to be programmed?

Following the installation of a new camshaft sensor, it’s important to reprogram it using a scan tool. This action aids in erasing stored trouble codes. Additionally, disconnecting the battery for around 14 to 18 minutes is advised. This pause allows the engine control unit (ECU) to readjust and reacquire its proper positioning.

How long does a camshaft sensor last?

The camshaft position sensor is designed to endure throughout the vehicle’s lifespan without a predetermined maintenance timeline for replacement. It’s only necessary to change it when it becomes damaged or malfunctions.

Why is the camshaft position sensor important?

A camshaft position sensor plays the role of a detective for your vehicle’s ECM/PCM, providing critical information about the camshaft’s rotation and position. This data is crucial for accurately determining the positions of intake and exhaust valves across both Bank 1 and Bank 2. This synchronization is tied to the functioning of lifters and pushrods.

Does a bad camshaft sensor throw a code?

Indeed, a faulty camshaft position sensor usually triggers an error code, often leading to the illumination of the check engine light. A bad camshaft position sensor triggers P0340, P0341, P0342, P0343, P0344, P0345, P0346, P0347, P0348, or P0349 code. However, it’s important to note that this doesn’t always imply the sensor itself is defective. Wiring problems between the ECM and the sensor, or difficulties in how the ECM interprets sensor signals, can also be contributing factors.

What causes camshaft sensor failure?

The primary reasons for a faulty camshaft position sensor encompass factors like a crankshaft walking, faulty wiring, engine overheating, and damaged timing belt, among others. The accumulation of oil within the engine, moisture, and normal wear and tear may also lead to the camshaft sensor failure.

Is it hard to replace a camshaft position sensor?

For many vehicles, the replacement of the camshaft position sensor is a relatively straightforward job, though this can vary based on your vehicle’s make and model. If you lack the confidence to perform the repair on your own, it’s recommended to have a professional address the issue for you.

How to reset the camshaft position sensor?

Unfortunately, there’s no method to reset a camshaft position sensor. If you are encountering problems like engine stall, stuttering, difficulties in driving, or check engine light, you might have to think about replacing the whole camshaft. Depending on your comfort level, you can choose to tackle this task on your own or hire a mechanic to handle the camshaft sensor replacement.

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