The crankshaft position sensor plays a crucial role in the proper functioning of a vehicle’s engine. It provides essential information about the crankshaft’s rotational speed and position to the Engine Control Unit (ECU), enabling precise fuel injection and ignition timing. However, when this sensor malfunctions, it can lead to a range of issues that affect engine performance and overall drivability.
While there are no true temporary fixes for a faulty crankshaft position sensor, there are steps you can take to troubleshoot intermittent problems associated with this vital component.
What Does the Crankshaft Position Sensor Do?
The crankshaft position sensor plays a vital role in monitoring the position of the crankshaft in internal combustion engines, including both diesel and gas-powered ones.
Its primary function is to relay this information to the vehicle’s computer, which utilizes the signal to regulate fuel injection and ignition timing. When used alongside the camshaft position sensor, the crankshaft position sensor ensures that the engine operates smoothly and harmoniously.
Where are the crankshaft position sensor located?
The location of the crankshaft position sensor varies depending on the vehicle. It is typically found on the main crank pulley or the flywheel, towards the lower part of the engine bay. The sensor has a distinct appearance that makes it easy to identify. However, if you are unsure about the location of the sensor in your specific vehicle, you can always refer to online resources that provide images and diagrams for different makes and models.
Symptoms of a Faulty Crankshaft Position Sensor
Check Engine Light
The engine warning light may illuminate well before the crankshaft sensor begins causing issues. The initial error code could indicate an “intermittent crankshaft position sensor problem,” signaling the need for sensor replacement at an early stage.
As other symptoms manifest, the error will no longer be deemed “intermittent” and will persist. To accurately identify your vehicle’s problem, connect an OBD2 scanner and retrieve the error codes.
Misfire
A misfire can occur when there is a problem with the crankshaft position sensor. This sensor needs to be synchronized with valves, injection, and ignition timing. When it fails, it can cause a number of issues, including misfires.
Misfires refer to combustion that happens either too early or too late, resulting in poor performance, reduced fuel economy, and increased emissions. If not addressed promptly, this issue can potentially lead to significant engine damage.
Engine Shudder
The engine is optimized to run smoothly, generating minimal vibrations. When the crankshaft position sensor malfunctions, the engine loses synchronization, resulting in shuddering, shaking, and potential stalling.
Mechanical vibrations pose a significant threat to machinery, particularly the engine. Driving the vehicle under these circumstances is not advisable as it can lead to heightened wear and damage to components.
Performance Issues
When the crankshaft position sensor in your vehicle is faulty, it can lead to various performance issues. These issues include a decrease in engine power, difficulty reaching higher RPMs, and the possibility of experiencing engine knock.
Essentially, when the crankshaft position sensor is not functioning properly, your engine won’t be able to generate its usual power. This can make your vehicle feel sluggish and less responsive. If you try to rev the engine to higher RPMs, you may notice a knocking sound, which is an indication of a problem.
Moreover, it’s important to address this problem promptly because it can have additional undesirable consequences.
A faulty crankshaft position sensor can result in increased fuel consumption, higher emissions, and even accelerated engine wear.
Temporary Fixes for the Crankshaft Position Sensor
While there are no temporary fixes for a faulty crankshaft position sensor, there are some steps you can take to troubleshoot intermittent sensor-related problems. Resetting error codes will not solve the issue as it will either reappear when you restart the car or simply hide the problem temporarily.
One potential solution is to disconnect and reconnect the power plug of the crankshaft position sensor and reset the Engine Control Unit (ECU).
If the sensor problems continue to occur after trying this, it indicates that the sensor needs to be replaced.
How to Replace the Crankshaft Position Sensor
Replacing the crankshaft position sensor is a fairly simple task that usually involves securing it with a single bolt or screw. To begin, disconnect the power plug and remove the bolt to extract the old sensor.
However, locating the sensor within the engine compartment can be the primary obstacle, as its position may differ among vehicles. Generally, it can be found in the region between the transmission and the engine, near the flywheel.
How Do You Test a Crankshaft Position Sensor?
In order to test the functionality of a crankshaft position sensor, you will require a test lamp. Crankshaft sensors come in two variations: 2-wire and 3-wire models, each with its own distinct testing procedure.
How to Test the 2-wire Crankshaft Position Sensor
To test a 2-wire crankshaft position sensor, follow these steps:
- Disconnect the crankshaft position sensor.
- Connect a test lamp to the positive terminal of the battery.
- Turn the ignition switch to the “On” position.
- Tap the terminals of the sensor quickly and repeatedly.
- Listen for a clicking sound from the spark plug, which indicates that the sensor is functioning properly.
How to Test the 3-wire Crankshaft Position Sensor
Here’s a simplified and clearer version of the instructions for testing a 3-wire crankshaft position sensor:
- Disconnect the crankshaft position sensor.
- Attach a test lamp to the negative terminal of the battery (for a 3-wire sensor).
- Turn the ignition to the “On” position.
- Gently tap the middle terminal of the sensor.
- If you hear a clicking sound from the spark plug, it means the sensor is working.
These tests help you determine if the vehicle’s computer is properly responding to the sensor signal. The clicking sound indicates that the sensor is functioning correctly. Remember to connect the test lamp to the positive terminal if you have a 2-wire sensor, and to the negative terminal if you have a 3-wire sensor.
I’m Timothy Ballard, owner of a used car dealership in Springfield. I love just about everything automotive, but I have a special place in my heart for trucks. I’m an ASE Certified Master Technician, so I know my way around a car. In my spare time, I enjoy traveling with my family and hiking new trails.
The crankshaft position sensor plays a crucial role in enabling your car’s engine to accurately adjust its timing and performance metrics. When there is a computer malfunction, these metrics can become imbalanced or maladjusted. However, a simple solution is to restart the engine, even for just a few moments, as this can effectively reset and restore the balance of these metrics.