How to Check if Camshaft Position Sensor is Bad (2 Best Ways)

How to Check if Camshaft Position Sensor is Bad

The best way to check if your camshaft position sensor is bad is through your odometer. If the camshaft sensor is bad, the check engine light warning will appear on the odometer notifying you that something is wrong. Use a scan tool to scan the code and have it replaced.

Do you often wonder how a car functions? Or particularly, how the engine of a car works? Well, the camshaft is a crucial, critical, important part of a working engine. It isn’t exactly a single thing, as it is made up of two components, the cams, and the shaft.

The camshaft is the part of the engine that controls the valves, enabling the engine valves to open up, taking in and exhausting valves in line with the crankshaft gear. Its movement is rotation, and as it rotates, the cams – also known as the lobes – shove the valves open, moving along with the gear.

The camshaft must move in line, specifically with the position of the cylinder else the engine will not function properly, and the workings of the car will be in jeopardy.

When the camshaft isn’t in the right position, or when the sensor of the camshaft position is bad, there might be no way to tell if our engine is right until the car breaks down. This is why knowing how to check the camshaft position sensor to know whether it is in the perfect state is very necessary.

Causes of Bad Camshaft Sensor

The camshaft sensor is used to send the necessary information to the engine control module of your car for the engine to sense the ignition time together with the fuel running of your vehicle.

This fails sometimes, causing data not to be passed to the engine control module as expected, and there can be various reasons for this failure.

Before some of the causes are highlighted, you should know that there are easy fixes to the problem, and it would help if you don’t panic. Here are some of the causes:

1. Walking Crankshaft

Motorists or mechanics also identify this as ‘crank walk’. This is used to describe the slipping or gliding of your engine’s crankshaft to the belt area of the engine, where it is not supposed to be.

Your crankshaft might begin to slip up or glide around when the main core of your engine starts to wear out as a result of time, or cracks for one reason or the other.

The more this phenomenon continues and the crankshaft keeps slipping and gliding without you taking notice of it, soon enough, the crankshaft will take up a new position and stay there, vacating its original position and causing further and faster wearing out of the core of the engine.

With the crankshaft in a new, unnatural position, the metal plate will hit the sensor over and over again as the belt of the engine revolves properly.

The more the sensor takes the hit, the more the crankshaft will weaken, and the weaker it gets, the worse it becomes.

In worst-case scenarios, the crankshaft breaks up, causing the engine to stop functioning as a result of a failure of the camshaft. 

2. Frequent Minor Accidents

Many drivers are reckless, and from time to time, they run softly into poles or collide with another car. After the minor accident, they might ignore going for an inspection of the car when they see that the car still functions properly.

Many of them just try to replace whatever aesthetics of the car that might have been bruised, without taking cognizance of the possibility that their engine might have been affected.

Small, frequent collisions can cause wire contractions, displacements, and damages inside the car. Also, it can loosen bolts that are meant to be toughly tightened, parts of the engine, such as the oil tanks, radiator, etc., to start leaking. Little damages like this, in the long run, will affect the camshaft sensor of the car and stop the engine from working.

3. Overheating

The camshaft of your car can get damaged when you drive for several hours nonstop, especially on a very hot day. The heat that your engine produces, along with heat from the sun will cause your car to overheat.

Even, the heat from the sun doesn’t have to contribute if you drive nonstop for long hours. The heat from your engine is just enough to cause overheating.

Drivers are also in the habit of not protecting their cars from the sun, thinking nothing can go wrong. Well, once your car becomes extremely hot, overheating occurs, and overheating can have a huge bad effect on the inner workings of your engine.

The hotter your car gets, the more your engine overheats, and as your engine overheats, the plastic around your engine, such as the cover of your crankshaft sensor, starts to melt or crack.

When this happens, the camshaft sensor will not be able to perform its duty of transporting fuel and data to the engine of your car.

4. Wiring Problems

Bad wiring can cause contractions, sparks and lead to problems for your camshaft sensors. Bad wiring can be a result of minor accidents as stated earlier, or bad workmanship after repairs.

A bad wire will cause your camshaft sensors to fail and make your engine grounded, no matter how hard you try to start it.

Signs that Camshaft Position Sensor is Bad

Like the symptoms that occur when a person is ill, your car will reveal certain symptoms when something is wrong with the engine, such as a bad camshaft position sensor.

Here are some of the signs to know that your camshaft position sensor is bad:

1. Ignition Problems

It will take longer periods, and a lot of trying before your car can ignite. This means that the camshaft sensor isn’t sending the right message to the engine, or powering enough fuel to enable the engine to start.

2. Car Surging

While driving, your car might begin to surge or jerk, that is, the engine will start to fluctuate, causing your car to shake. The engine’s power might go off and on, low and high as it is trying to find a balance but will not. At the end of the day, it will go off suddenly once the energy in the engine dies off.

3. Bad Acceleration

Your car will have an issue accelerating because the camshaft is bad, making your engine run poorly or slowly, and not passing the right message to the right parts of the vehicle. Once the camshaft sensor starts to fail, your car might not go higher than 30 mph.

4. Bad Gas Mileage

More fuel than necessary will be consumed on even lower miles per hour because of the amount of fuel expended on trying to accelerate and get the car to run at the proper speed. To increase your gas mileage, check that the sensor is in order.

How to check if Camshaft Position Sensor is bad

Check Engine Light

Coupled with the other signs, once there is an issue with your camshaft position sensor, or any issue at all in your engine, the ‘Check Engine light on your dashboard comes on.

The light, as the name explains, indicates that something is wrong with your engine, and you should check it out. More than half of the time, it is the camshaft position sensor that is bad.

This is the car’s way of letting you know that your camshaft position sensor is bad, even if you know next to nothing about handling car repairs, or you are a rookie driver.

Once you see the engine light illuminate, it almost always means that there is something awry wrong with your camshaft position sensor.


Ensure that you are always checking your dashboard for the “Check Engine” light before getting your car on any journey to avoid accidents. Once you notice that your check engine light is on, the onus rests upon you to check your engine to see if the camshaft is bad. If it is, take it to the nearest mechanic and repair your camshaft sensor before you get your car on the road for any journey.