When key fobs malfunction, one of the most common culprits is a dead battery. However, there are situations where replacing the battery isn’t sufficient. Can you reset your key fob so that it can work again?
Under normal circumstances, your key fob will not lose its programming if the battery goes dead. The programming is stored in the key fob’s non-volatile internal memory by design and does not require power to retain the data.
Once you replace the battery, the key fob should function as usual.
However, if the key fob still doesn’t work after replacing the battery, it might need to be re-synced with your vehicle. This is a rare occurrence, particularly on vehicles built in the 21st century, but sometimes key fobs can malfunction after their little batteries go dead so that the key can lose its programming. This means the key fob and your vehicle might have gone out of sync. To fix the issue, you need to reset a key fob, which involves reprogramming either the key fob or the vehicle to work in sync.
Each key fob has a unique identification code that was programmed into the fob when it was made. This code is transmitted when you press the button and your vehicle receives the signal, unlocking the door only if the signal transmitted the code.
Replacing a battery doesn’t replace the unique identification code transmitted, so it should still work with your vehicle. However, some older vehicles have key fobs that work differently. These key fobs can lose their memory or programming when the battery dies. Hence, they’ll need to be reprogrammed to work again.
That said, reprogramming the key fob isn’t always the best first course of action. If you have a problem, don’t reach out to your dealership just yet. You might be able to resolve the problem with these troubleshooting tips.
If your key fob is not working, one of the most common issues is a dead battery. Replacing it is relatively simple. Simply open the fob with a flathead screwdriver and replace the battery inside.
You can check whether the battery works or not by using a multimeter or a battery tester, or you can just replace the battery to see if it brings the key fob back online.
If you want to use a meter, just set its direct current (DC) setting and touch the leads to the opposing sides of the battery. CR2032 or CR1616 batteries should have voltages that measure around 3V. If the battery measures below 2.7V, then the remote won’t function correctly.
If you don’t have a multimeter, you can use your spare key fob’s battery to determine whether the battery works. You can keep some batteries on hand; they don’t cost much.
Key fobs are typically composed of a plastic housing and a chip that has three parts: a short-range radio transmitter, an RFID chip, and an antenna. This chip uses radio frequencies to send a coded signal to your vehicle’s receiver.
Inspect the housing for damage. The key fob can get crushed if they’re often placed in tight spaces, like crowded pockets and compartments. Most key fobs also aren’t waterproof. If they get wet, the moisture can ruin their circuitry. Issues can also arise from the membrane switches, which can fail from use.
Some areas have interference that might affect your vehicle’s ability to receive radio signals from the key fob. Pressing your key fob closer to the receiver could resolve this issue.
Note that the receiver’s location can vary depending on the vehicle. Sometimes, it can be located in the center console or under the rear cargo area. Repeatedly press your key fob as you move the key fob around the vehicle. This might allow your key fob’s signal to finally reach the vehicle.
If you unlocked your vehicle and the problem didn’t persist in a different location, then the problem was probably interference.
If the previous measures don’t fix the issue, then reprogramming your vehicle’s key fob is the last resort.
Programming procedures can vary greatly depending on a vehicle’s make, year, and model. For example, some can involve starting your vehicle several times in a certain sequence and timing to set the vehicle into programming mode. This process can be quite complex, and we recommend doing your research and checking out a procedure that’s specific to your vehicle.
On Fords, you can rapidly switch the key to the “on” position until you hear the doors lock and unlock. When you hear that, leave the key on and press a button on each fob you want to program and you’ll hear the doors lock and unlock each time. Then switch the key off and the doors will lock and unlock again, and you can check to see if your fobs work.
Your vehicle’s owner’s manual might have information regarding programming key fobs. You might also find the information at sources like ProgramYourRemote.com.
If you can’t troubleshoot the issue, then your last course of action is to reach out to a local dealership. Some key fobs might require specialized tools to be reprogrammed.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.