Car Key Fob Problems: 4 Common Issues & Solutions

The use of physical keys has slowly declined as radio and Bluetooth technology has become the norm with automobiles and security authentication.

Key fobs provide convenience to enter and start your car, but when they don’t work, they can also complicate using your car.

We’ve gathered a list of common issues to be aware of and the solutions to fix each situation.

These should help keep your key fob as a convenience and prevent it from becoming an annoyance.

#1 – Your Fob Only Works Next To The Car

Most key fobs have a range of up to 50 feet where they will unlock or lock your doors. In some situations, such as a significant change in elevation, your fob will work from a farther distance.

As the battery inside the key fob loses charge with every use, eventually the range will get shorter and shorter.

A cold key fob can barely work at all, and you may need to stand next to your car for it to register.

How to Fix It

Both situations, the reduced distance over time and the cold, indicate that the battery inside your key fob is slowly losing charge.

Most key fobs use a small flat battery the size of a dime that you can buy at a retail store that sells batteries. When the battery has a minimum charge left, it’s best to replace the battery.

The key fob can be opened using a small flathead screwdriver or a small prying tool. Once the two halves of the key fob are open, the battery can be taken out and replaced.

If you have any questions about the process, your car owner’s manual should describe the process.

#2 – You Need To Push The Buttons More Than Once

A functional key fob should work with just one push of a button. It doesn’t matter if it’s the unlock, lock, trunk, or another combination of buttons.

One click and it should work, period. If you must push the same button multiple times or change your position for it to work, you have a problem to deal with.

How to Fix It

If you must push the buttons a few times for the key fob to work, the signal from the key fob isn’t being registered by the car.

The battery in the key fob could be drained and need to be replaced. If you don’t know which type of battery is inside your key fob, you can open it with a small screwdriver or prying tool and read the number on the battery. They are sold at most retail stores, whether online or in a physical location near you.

A second possibility is that the battery has plenty of charge, but the signal isn’t being transmitted by the key fob.

The fob has a circuit board with a transmitting antenna inside that sends the signal to the car. It can be damaged if the key fob is dropped on a hard surface.

You can test if one key fob is bad if you have two separate units. The one that hasn’t been dropped should work better than the suspected unit. The damaged key fob may need to be replaced with a new one.

The last possibility is that something in the car is preventing the signal from being registered by the car. Aftermarket electronics that are installed near the control module inside the car can emit a signal that blocks the key fob signal.

It’s not a common problem, but it can happen. In this case, the new installation may need to be changed to prevent blocking the original key fob signal.

#3 – The Key Fob Won’t Start The Car

If your car is a few years old, it may use the key fob for multiple purposes. It can unlock doors, open the trunk or hatch door, and it may send a signal to start the car.

Your key fob may work part of the time, only triggering the door locks, and it won’t notify the car to start. Is it the key fob or something else causing this?

How to Fix It

If the key fob works for some of the functions, it should work for all functions.

The door locks don’t require a large surge of power to move, but starting the car does require a large amount of power. If the car won’t start, such as the starter won’t try and turn the engine, it may be due to the battery cables having a poor connection.

You may hear a click when the car tries to engage the starter, and nothing else happens.

The first place to diagnose the problem is at the battery. Check that both cables have a secure connection to the battery terminals.

If you find the cables have corrosion on the terminals, the corrosion should be removed, and the battery cables properly secured.

If that doesn’t cure the intermittent problem, check the opposite end of the cables at their respective connections to the starter solenoid and the grounding point to the car.

Please also read our article, 7 Popular Cars Without Key Fobs

#4 – The Key Fob Has Stopped Working

A weak key fob battery and a partially damaged key fob may work in limited situations. Sometimes the key fob just doesn’t work anymore.

It won’t start the car and it won’t unlock the doors. You may not be able to use the car, or you need to use the manual key to unlock the doors and start the car. It’s an inconvenience if you’re used to a key fob doing everything.

How to Fix It

If the key fob stops communicating with the car, you can guess it’s either the car or the key fob having a problem.

The battery inside the key fob is dead, the key fob has stopped sending a signal, or the car isn’t communicating with the key fob.

If the battery was almost out of power, you should have noticed that it required the buttons to be pushed more than once and it needed to be closer to the car to work.

The battery can easily be replaced if it dies, but the key fob may need to be registered to your car again. Some manufacturers require a trip to a dealer for the registration process if you can’t do it yourself.

If the battery has a charge, the key fob could be damaged. We’ve seen cases where the key fob was dropped onto a hard surface, or it was run over by the car. Weird things do happen, and they render the key fob damaged beyond repair.

The key fob needs to be replaced or you can use a spare key fob to operate the car.

The last option is that the car doesn’t recognize the key fob anymore.

The car may display a message in the gauge cluster of “Key Not Detected” or “No Key Present” because the car doesn’t detect the key fob or the key if it has a registration chip.

This can be caused by a weak or dead key fob battery, or something electronic like a cell phone or laptop could be interfering with the key fob communication. It may be a simple solution to remove the electronic device or replace the key fob battery as previously suggested.

Can I Start My Car With A Bad Key Fob?

You may think that your car won’t work if the key fob is bad, or it has stopped communicating with the car.

Your car should have an emergency start procedure that may require you to step on the brake pedal and then press the start button with the key fob or key (and not your finger).

Some models may require the key fob to be placed in a slot next to the steering column or in a center console and then the tip of the key used to push the start button.

Your car should have an emergency start procedure, so check the owner’s manual to determine each step in the process if your key fob isn’t working with your car anymore.

You won’t be stranded away from home, and it will allow you to return home to start the diagnostic process to find out what the issue is.

Read here for common car ECU problems and solutions.

Was this article helpful?