Symptoms Of A Bad Crankshaft Position Sensor – Rx Mechanic

What is an engine without a crankshaft or the crankshaft position sensor? This component is crucial to the engine’s ability to generate power to move a vehicle from one place to another.

The crankshaft position sensor is an essential engine management sensor. It works together with the other components like the Powertrain Control Module (PCM) within a car’s engine compartment to generate power for the engine.

A slight defect on the crankshaft sensor can be a big challenge for a vehicle’s engine because it may not start. Besides that, several symptoms of a bad crankshaft position sensor are discussed in the subsequent sections below.

How does Crankshaft Position Sensor Work?

The crankshaft is a vital component in ensuring a vehicle’s engine starts and runs effectively. The crankshaft works hand-in-hand with the pistons to generate power for the engine.

Meanwhile, the crankshaft position sensor is responsible for monitoring the location of a vehicle’s crankshaft and accessing the speed of the crank’s rotation. While this is on, the Powertrain Control Module then receives the information transmitted by the crank sensor.

The information is further utilized in determining the ignition timing and the regulation of the fuel injection process in the vehicle’s engine.

Also, the reluctor ring’s teeth attached to the crankshaft pass near the crank sensor’s tip. It generates a pulsed voltage signal sent to the Powertrain Control Module (PCM). The PCM then utilizes the data from this signal to create an ignition spark for a specific cylinder.

If there is an interruption in the process of the crankshaft position sensor sending the signal to the Powertrain Control Module, no ignition spark will be created on the cylinder, and no fuel will be sent to the injectors to function.

So, you may be wondering what causes a crankshaft sensor to go bad. The causes may include a faulty wiring harness, loose wiring, etc. Back to our topic of discussion! Let’s take a look at some common signs of a bad crankshaft positions sensor.

Symptoms of a Bad Crankshaft Position Sensor

The malfunction of the interaction between the crankshaft sensor and the Powertrain Control Module causes a vehicle to stall, misfire/backfire, and eventually refuse to start after a while. Meanwhile, some symptoms of a bad crankshaft sensor include:

Check Engine light display

The Check Engine light is undoubtedly triggered by several malfunctions that may occur not only within the crankshaft sensor. However, it is one of the foremost noticeable symptoms of a defective crank sensor.

If a vehicle’s Check Engine light displays and remains on for a while, endeavor to find out what may be wrong. If you are not sure, kindly consult an expert auto mechanic/technician to check it out.

Excessive vibration

Part of the crankshaft position sensor’s responsibility is to monitor and minimize a car’s engine vibration to have a steady energy output. So, if the sensor goes bad, the vehicle’s engine will automatically start vibrating excessively.

When this occurs, the vehicle’s mileage may be difficult to measure correctly, which is an important reason why the problem must be rectified immediately.

Reduced engine acceleration

Another sign that reveals that a vehicle crankshaft position sensor is faulty is the reduction in the vehicle’s ability to accelerate optimally.

Since there is an interruption of the communication between the sensor and the Powertrain Control Module (PCM), the time taken to determine the position of the cylinders will automatically affect the vehicle’s accelerator. This can also hinder the vehicle’s speed.

Engine stalling/backfiring

The interruption of the interaction of the crankshaft position sensor with the other engine components can also cause a vehicle to backfire and stall.

Hence, if a vehicle’s engine shuts down again after starting or sustains a while but stalls on the road and eventually stop, it is most likely due to a faulty crankshaft sensor. This may appear as a minor problem at first, but can be detrimental to the engine if not rectified quickly.

Engine start difficulty

Engine start difficulty can also result from a number of challenges, including electrical faults. If you find out that a vehicle fails to start, check the wire connections and the plugs.

If the wiring and plugs are intact, a faulty crankshaft position sensor may be responsible for the difficulty experienced in starting the vehicle’s engine. For people who are asking, “Can a faulty crank sensor result in no start?” This is a perfect answer for you.

However, if you experience this challenge, endeavor to consult a mechanic to diagnose why your vehicle fails to start.

If you own a Chevy and are experiencing these signs discussed above, they are also common symptoms of a bad crankshaft sensor in a Chevy or any other car. It would be nice to see an expert mechanic asap.

How do you Test a Crankshaft Position Sensor?

A crankshaft position sensor can be tested with the help of a scan tool (e.g., OBDII Scanner). However, not everyone can access a scan in some cases, except a rented one.

There is another common way to test a crankshaft sensor, and that is with a multimeter. To test a car’s crankshaft position sensor:

• Locate the sensor’s plug and remove the crank sensor.
• Attach each of the multimeter’s ends to the sensor’s wiring lead.
• Once this is done, check the reading on the multimeter.

If the multimeter reads zero (0) or displays an infinite resistance, it means the crankshaft sensor is bad. But if it shows anything other than zero or infinite resistance, endeavor to check it against the ideal reading from the vehicle’s manufacturer’s manual.

Finally, if the reading is not close to what the manual recommends, you may need to replace the crankshaft position sensor.

FAQs:

Q: Can a vehicle work without a crankshaft sensor?

A car cannot run without a crankshaft sensor because it is an essential component among other sensors that interact with the engine. The sensor is so sensitive in the engine running process, from the ignition spark.

So, if you have a defective crankshaft position sensor, your car’s ignition spark will be hindered; and the effect will be a difficulty in starting the vehicle’s engine.

If you face this kind of challenge, it would be best to consult an expert auto mechanic to rectify the issue as soon as possible.

Q: Can I reset my crankshaft sensor?

Yes, you can reset your vehicle’s crankshaft position sensor. If a vehicle’s engine stalls consistently and eventually goes off without starting for a long time, it is most likely that the issue is traceable to a faulty crankshaft position sensor. The crank sensor may require a reset.

To completely reset a vehicle’s crankshaft sensor, simply do the following: turn off all accessories in the vehicle, then start the vehicle’s engine and allow it idle for about 2 minutes while on “Park” or “Neutral.” After that, accelerate the car at 55 mph.

Then cruise at the same 55 mph for about 8 – 10 minutes to get the vehicle engine at operating temperature. Again, cruise for some more 5 – 6 minutes. Then, decelerate down to 45 mph without applying the brakes.

Now, perform at least 4 decelerations of 25 seconds each and return to 45 mph for about 15 seconds between each deceleration.

Finally, accelerate back to 55 mph for 2 minutes and stop the vehicle. After that, idle for about 2 minutes while the brake is applied, and the clutch is depressed.

Q: How do you jump a crankshaft sensor?

Jumping a crankshaft position sensor in a car depends on the state of the crankshaft position sensor’s fault. In any case, if you can access a mechanic, it would be better to do so; if not, you can find out how to start a car with a bad crankshaft position sensor.

To perform a temporary fix for a crankshaft position sensor, simply locate the vehicle’s crankshaft position sensor plug and remove it. After that, apply a starting fluid.

Then, start the car again. You’ll be lucky to have the car’s engine start after this process because, in most cases, a defective crank sensor usually requires a complete replacement.

Q: How often should you change crankshaft sensor?

A vehicle’s crankshaft position sensor does not easily go bad, but it is subject to wear and tear; hence, it would require a replacement at that time.

The primary reason that will require a prompt replacement of a vehicle’s crankshaft is when the car starts manifesting the symptoms of a bad crankshaft sensor.

Besides that, if you discover that your car’s fuel consumption economy is getting poorer by the day, it calls for a diagnosis of the crankshaft sensor in case you would need to replace it.

Q: How much does it cost to replace a crankshaft sensor?

Replacing a crankshaft sensor does not cost a fortune. The estimated price for a crankshaft sensor replacement is around $194 to $258. Labor costs may vary between $104 and $133, while the parts could be valued at $90 to $125.

However, the cost of replacing a crankshaft sensor may differ from one location or service provider to another. So, it would be best to check out an automobile parts seller and a service provider near you.

Q: Can I bypass a crankshaft sensor?

No, you can’t bypass a crankshaft sensor to enable it to work again after it goes bad. If you manage to devise some manipulations on it, it may crank and not power the vehicle’s engine to start.

The best thing to do when a car’s crankshaft position sensor becomes faulty is to replace it as soon as possible. It doesn’t cost a fortune to replace so that the engine is not completely damaged.

Q: What happens if you drive without a crankshaft position sensor?

If you drive without a crankshaft position sensor or a faulty one, the vehicle will consistently stall on the road at all speeds and eventually stop. Apart from that, you will experience excessive vibrations from the engine.

Also, the most severe occurrence would be when the vehicle stops, as it may be challenging to start the engine again. Therefore, once you notice that your car’s crankshaft sensor may be faulty, it would be best to consult an expert auto mechanic to check it out quickly.

Final Words

A crankshaft position sensor is as important as other Sensors that make your vehicle work effectively. The part plays a vital role in generating power for the engine.

So, you shouldn’t try to manage the symptoms of a bad crankshaft positions sensor. Another thing you shouldn’t also try to manage is the symptoms of a bad camshaft sensor.

If you notice any of these symptoms discussed above in this article, endeavor to seek the service of a professional auto mechanic. In any case, the worst burden would be to replace the crankshaft sensor, which does not cost a fortune.