Why Is My Key Fob Not Working In Cold Weather? 5 Causes and Resolution!

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key fob not working in cold

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Cold weather can be a formidable adversary, especially when it comes to remotely starting your vehicle. Sometimes, your key FOB may not work in cold temperatures, putting you in hassle.

So, why is your key fob not working in cold temperatures? Key fobs can malfunction due to weakened batteries, sluggish car batteries, frozen fuel lines, thickened engine oil, and carburetor issues.

To get rid of this adverse situation, learning how to address the issues is crucial. Read on as I explain these causes and the solutions to this common winter problem.

key fob not working in cold

Why Is My Key Fob Not Working In Cold Weather?

Cold weather can wreak havoc on the delicate systems that allow your key fob to communicate effectively with your vehicle. Here are some of the most common reasons why your key fob will not work in cold temperatures.

1. Fob Batteries Are Affected By The Cold

Key fobs rely on small batteries to transmit signals to your vehicle. Unfortunately, like most batteries, cold weather can significantly impact key fob battery performance, too.

Cold temperatures slow down the chemical reactions happening within these batteries. This reduced chemical activity translates to a diminished capacity to generate electrical power.

This is why the signal sent to your car may be too weak to register when you press the buttons on your key fob.

Solution

First, take the key fob somewhere warmer, like your living room, and leave it there for a few minutes. The key fob should be able to work after this. However, if it still doesn’t work, you will have to replace the batteries. Here is how to replace them.

Step 1: If your key fob has a visible screw, use a small screwdriver to remove it. If you have a key fob with a coin slot, insert a coin and twist it gently to unlock the compartment.

Step 2: Carefully remove them by gently prying them out using a flathead screwdriver or your fingernail.

Step 3: Take the new batteries and align them in the same orientation as the old ones. Then, close the battery compartment, ensuring it locks securely.

2. Your Car Battery Isn’t Generating Enough Electrical Current

It’s not just your key fob’s batteries that suffer; your car’s battery faces similar challenges when the cold sets in. This is especially true if your car’s battery is old; the older it is, the weaker it will get in cold temperatures.

If your car’s battery is struggling due to the cold, it may not provide sufficient power to support the keyless entry and ignition systems.

Solution

If your car battery gets affected by cold weather, you can start by jump-starting it. If that doesn’t work, then it is time you replace it. Here is how to do it.

Step 1: Open your vehicle’s hood and locate the battery. Then, disconnect the negative terminal followed by the positive one with a wrench.

Step 2: Use your wrench to loosen and remove any securing components. Once free, lift the old battery out of its tray.

Step 3: Carefully place the new battery into the battery tray. Then, secure it with the bracket or hold-down clamp you removed earlier.

Step 4: Reconnect the positive and then the negative terminal, ensuring you securely tighten the bolt or nut using your wrench or socket set.

3. Your Car’s Fuel Lines Have Frozen

Cold weather causes fuel to congeal or, in extreme cases, freeze solid. This fuel thickening makes it less fluid and more prone to forming blockages within the fuel lines.

When your vehicle’s engine doesn’t receive an adequate fuel supply due to frozen or congealed fuel lines, it may not start. This lack of fuel can also be why your key turns without resistance.

Since your key fob relies on a functioning engine to operate, any issue with the fuel lines can render it ineffective.

Solution

You will have to unfreeze these fuel lines to mitigate this issue. Here is what you need to do.

Step 1: Identify the frozen fuel lines in your vehicle. You will find them along the underside of your car, leading from the fuel tank to the engine.

Step 2: Slowly apply heat gently using a portable heater, heat gun, or warm water.

Step 3: Allow the heat to work on the frozen fuel lines. Depending on the severity of the freezing, this may take about half an hour.

Step 4: Now, attempt to start your vehicle. If the fuel lines have thawed, the engine should start without issues. If the engine struggles to start, you should repeat the heating process until the fuel lines are completely thawed.

Preventative Measure:

To prevent fuel lines from freezing in the future, consider adding a fuel line antifreeze additive to your gas tank.

4. The Engine Oil Has Become Thick

As the temperature plummets, the viscosity of engine oil increases as well, making it thicker. Thickened oil poses challenges to the engine’s components, making it harder for them to move freely and function optimally.

When your engine struggles to respond promptly due to thickened oil, it affects your key fob’s ability to communicate effectively with the vehicle.

Solution

You will have to thin out the engine oil in your car or have the oil changed altogether. As this is a complex process, I recommend that you seek professional assistance on this one. The good thing is that it will cost you about $100 to have this done.

5. Carburetor Issues

If you have an older vehicle with a carburetor, cold weather can pose additional challenges. Carburetors regulate the air-fuel mixture in the engine, and they can malfunction when exposed to extreme cold. However, when exposed to extreme cold, carburetors can malfunction.

A malfunctioning carburetor can prevent your vehicle from starting or running smoothly. That is why any issue with the carburetor can translate into key fob unresponsiveness. After all, your key fob relies on the engine’s proper functioning for various operations.

Solution

If you suspect that the carburetor is the issue, you should follow these methods for remedy.

  • Cold Weather Carburetor Adjustment: Some carburetors can be adjusted for colder weather operations. Consult your vehicle’s manual or a mechanic to see if this is possible for your car.
  • Engine Block Heater: Install an engine block heater if you live in an extremely cold climate. This device warms the engine, making it easier for the carburetor to function in frigid conditions.
  • Consult a Professional: Have a professional mechanic inspect your carburetor for any issues. They will replace the carburetor if necessary, costing you about $500 to $2,000.

Conclusion

Your key fob not working in cold weather can be a frustrating experience, but it’s not an insurmountable problem. By understanding the potential causes of these problems and their fixes, you can ensure that your key fob operates reliably.

Remember, preparation and regular maintenance are key to keeping your key fob and your vehicle functioning smoothly year-round. Don’t let winter weather freeze your plans – take proactive steps to keep your key fob working flawlessly, no matter the temperature.

Resources

  1. https://www.pacificaforums.com/threads/fob-doesnt-work-when-cold.27722/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9062004/#:~:text=Amongst%20these%2C%20low%20temperature%20conditions,LIBs%20under%20low%20temperature%20conditions.
  3. https://groups.google.com/g/alt.autos.subaru/c/hPqen7VZ21k
  4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6104034/
  5. https://www.reddit.com/r/KiaNiro/comments/rvtzxb/does_anyone_else_have_issues_with_their_key_fob/

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