Will Disconnecting Battery Reset Crankshaft Sensor – Guide

If the battery needs to be disconnected, use the negative battery connector to do it. Then, reconnect the battery to turn off the check engine light after letting the car idle for an hour. This will drain the battery and wipe off any short-term memory.

What Does A Crankshaft Sensor Do?

A crankshaft position sensor (CKP) is used in internal combustion engines to track the location or rotational speed of the crankshaft. This sensor typically consists of a sensor located close to the reluctor wheel and a toothed reluctor wheel connected to the crankshaft. As the crankshaft turns, the reluctor wheel’s teeth encounter the sensor, generating an electrical signal.

Why Does The Crankshaft Sensor Fail?

A crankshaft position sensor (CKP) can fail for a variety of reasons. Among the most common causes are:

  • Wearing out: Over time and with exposure to heat, vibration, and moisture, the sensor may begin to lose its capacity to perform as intended.
  • Contamination: The sensor may become contaminated with dirt, debris, or oil and stop working.
  • Electrical issues: The sensor may malfunction as a result of a wiring or connection issue.
  • Mechanical problems: If the reluctor wheel or tone ring of the sensor is broken or worn out, the sensor may not work properly.
  • Heat exposure: The lifespan of the sensor can be shortened by a hot engine compartment.

It is significant to note that, if a faulty CKP sensor is not immediately fixed, a range of symptoms, including engine misfires, poor fuel economy, stalling, and trouble starting, may develop.

Will Disconnecting Battery Reset Crankshaft Sensor
Crankshaft Position Sensor

Symptoms of a Bad Crankshaft Position Sensor?

  • Engine misfires: The engine control module uses the crankshaft position information sent by the CKP sensor to time the ignition and fuel injection. The sensor could malfunction, causing the engine to misfire or run poorly.
  • Starting problems: A damaged CKP sensor might make it difficult or impossible for the engine to start.
  • Engine stalling: If the CKP sensor isn’t working properly, the engine may stall, especially when slowing down or coming to a stop.
  • Poor fuel economy: A malfunctioning CKP sensor can lead to poor engine performance and poor fuel economy.
  • Check engine light: The dashboard’s check engine light will turn on if the CKP sensor malfunctions.
  • Reduced power: If the sensor doesn’t give the engine control unit precise information about the crankshaft position, the engine control unit won’t be able to manage the engine properly, which will result in the engine losing power.

How to Reset the Crankshaft Position Sensor?

The CKP sensor may be reset by unplugging the battery, but this is not a guarantee that the issue will be resolved, and it may have consequences for other sensors or systems linked to the car’s computer. Additionally, the engine control module (ECM) might need to be reprogrammed following a CKP sensor replacement since otherwise it might not recognize the new sensor.

For the purpose of locating the problem’s primary causes and figuring out the best course of action, it is essential that the vehicle receive a thorough diagnosis from a specialist.


A crankshaft position sensor (CKP) cannot be definitively reset, and doing so is not advised. An electrical sensor called the CKP sensor alerts the engine control module (ECM) when the crankshaft is rotating. If the sensor malfunctions, a mechanic must diagnose it and either fix or replace it.

However after replacing it the crankshaft position sensor have to be relearn (Reset) to avoid errors such as the car won’t start or check engine light still on after replacing crankshaft. 

To Test A Crankshaft Sensor?

  • Using a multimeter: You can use a multimeter to check the sensor’s continuity and resistance. It is usual practice to unplug the sensor from the engine’s wire harness and measure the resistance across the terminals.
  • Using a scan tool: A scan tool can be used to track the sensor’s signal while the engine is operating. The output of the sensor can be shown by the scan tool in real-time, helping to spot any issues with the sensor’s signal.
  • Check engine light: If the CKP sensor malfunctions, the dashboard’s check engine light will turn on, signaling that there is a problem that needs to be looked at.

Can A Bad Battery Cause Crankshaft Sensor Problems?

Due to the crankshaft’s variable rotational speed, low battery voltage can contribute to a MIL On status for P0335 (Crankshaft Position Sensor ­Circuit) and/or P0340 (Camshaft Position Sensor ­Circuit).

  • Review the vehicle’s freeze-frame data and check the battery voltage to see if it was below the minimum specification of 11 volts when the DTC was set.
  • If it was, identify the cause and make the necessary repairs.
  • If the battery voltage is within specifications, follow the instructions in the relevant repair manual for the DTC that applies.

How Much Does It Cost To Reset/ Repair/ Replace The Crankshaft Position Sensor?

The majority of the time, a skilled mechanic can quickly identify a crankshaft sensor issue. Usually around an hour. The actual replacement is not challenging. Corrosion around the sensor, though, occasionally makes repairs take longer. A mechanic will understand how to change the sensor’s two components and how to correctly adjust their gap.

A crankshaft replacement in a standard car will cost the total of the parts plus the labor, which takes two hours or less on average. A new crankshaft sensor should cost between $200 and $400. The price may increase or even double if you drive a fancy or expensive car or one that is more challenging to access the sensor in. The majority of the time, brand-new, original equipment parts rather than aftermarket parts are used.

Where to Go If You Have a Crankshaft Issue Identified and Fixed

Any skilled mechanic should have no trouble diagnosing and installing a crankshaft sensor. You can trust any nearby business to complete this task. Would we suggest you take the vehicle to a chain mechanic for this kind of engine issue? Hmm. Only if you are certain that they have a dependable, skilled mechanic on staff.

The service department of every dealership can complete this task. But ultimately, you’ll pay more. Dealerships often charge 20% to 35% more for any given job since they have greater landed costs and labor costs than smaller independent businesses. By all means, employ the dealer for this work if your automobile is still covered by the warranty.

Is It Possible To Replace A Crankshaft Sensor Yourself?

For the majority of car owners, diagnosing and repairing a crank sensor is not a do-it-yourself project, unlike normal maintenance. You could try this project if you have an OBD2 scan tool and are confident with a multimeter, but the time it will take you might be more expensive than the time the project will save you.

Frequently Asked Questions:

Do you need to disconnect battery to change crankshaft position sensor?

Because the crankshaft position sensor is electrical, failing to remove it could cause both personal injury and vehicle damage. To access the crankshaft position sensor, you might need to remove the starter in some vehicles.

What causes crankshaft sensor damage?

The failure of the crankshaft position sensor can be brought on by a number of factors, including damage, debris, and defective circuitry. The engine is a hostile and harmful environment, even for modern electronics. Despite being constructed for this, the heat and vibration of the engine eventually cause most sensors to fail.

How to temporary fix for crankshaft position sensor?

Find it here…

What happens if I disconnect crankshaft sensor?

The computer uses the crankshaft position sensor (CKP) to locate the crankshaft on the #1 cylinder cycle and calculate when to time the spark and fuel injection. Without it, there won’t be any ignition and, frequently, no fuel injection, so the engine won’t start

About The Author

Avatar for Ibrar Ayyub

Ibrar Ayyub

I am an experienced technical writer holding a Master's degree in computer science from BZU Multan, Pakistan University. With a background spanning various industries, particularly in home automation and engineering, I have honed my skills in crafting clear and concise content. Proficient in leveraging infographics and diagrams, I strive to simplify complex concepts for readers. My strength lies in thorough research and presenting information in a structured and logical format.

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