Learn how to resurrect - or replace - your faulty key fob, with our handy guide. Plus, our FAQs cover everything from keyless ignition problems to what to do if you get your fob wet.
Key fobs have been a standard feature of most mass production cars since the mid-2000s, enabling the modern motorist to access their vehicle conveniently and securely.
However, all those advantages quickly go out the window if (or more likely, when) the key fob won’t work. In these moments, one can find oneself hankering after the simple reliability of the good old fashioned key.
That said, there are a number of steps you can take to fix keyless entry remotes, so you can get back on the road again.
Key fob not working? 4 things to try
Finding your car remote key not working can be inconvenient, and even a little scary if you're far from home when it happens. Run through these four steps to get your fob working again.
1. Battery check
It won't surprise you to learn that key fobs only work with a live battery in them. These cells only use a tiny amount of current, so can last three to four years. You can find a replacement online or at a bricks-and-mortar car shop.
You’ll need a very small screwdriver (e.g. size 0) to access the battery: ensure you use one with a good ‘bite’ since the screwhead can strip out easily - causing more problems than it solves.
The simple replace the battery and test it out. If it still doesn’t work, move on to the next step.
NB: It’s a good idea to replace the battery every two-and-half to three years, before it goes flat.
2. Reprogram key fob
Don’t worry, this step isn’t as complex as it might sound. It’s fairly straightforward to reprogram and fix key fobs.
What follows is a general guide to reprogramming a key fob; your owner’s manual will provide specific information on how to reprogram your model’s fob.
Access the programming mode
Get inside your vehicle and close all the doors. Next, put your key in the ignition and rotate it to the ‘on’ position, but without actually starting the engine. Most vehicles will make a particular sound or chime when the programming mode has been accessed. You may need to turn the key between ‘on’ and ‘off’ a few times before successfully entering the programming mode. Check your manual for more information.
Press and hold the key fob button
Next, simply press and hold the lock/unlock button for between 10 and 30 seconds - this should reprogram the key fob. Most vehicles will emit a chime or other noise to tell you the reprogramming process has been successful.
Test the fob
If it works, job done. If it doesn’t, move on to the next step.
3. Check for damage to the fob
Just like any other electronic device, a key fob can get physically damaged. Getting dropped and being stepped on, for instance, can damage the housing, buttons, battery or circuit board. If you suspect it has been damaged, consider opening up the fob and looking for any signs of trouble.
If you suspect the fob is damaged, take it to your nearest dealership. For security reasons you’ll need to show personal identification documents and vehicle ownership details before you can get a new fob, and you may be charged a replacement fee. However, if the fob has failed due to a manufacturer’s defect, it may be covered by the warranty.
4. Take it to a local mechanic
Another option is to take your inoperable key fob to your regular mechanic or a car shop/store that specialises in key fobs. They may be able to resolve the problem.
Damaged and inoperable key fobs: FAQs
Here are a few common questions about key fobs, and what to do when they go wrong.
Frequently Asked Questions
Locking one’s fob inside one’s car can make one feel a little foolish. But don’t worry - it’s a common mistake.
Unless you feel comfortable using a coat hanger (see below) - or similar piece of hard wire - to access your vehicle, your best bet is to call a locksmith who specialises in car locks. They have the tools needed to access your vehicle in just a few minutes. And best of all, you won’t have coat hanger scratch marks on your car afterwards!
NB: By doing the following you could damage the internal door components, the weather stripping, or the paint. You should also only consider it an emergency situation - and only on your own vehicle.
First, unwind a wire coat hanger and straighten it as much as possible, leaving a small hook at one end. Next, bend the tip of the hanger into a small hook shape; this will be used to manipulate the lock mechanism inside the door.
With the hanger ready, carefully wedge the hooked end of the hanger between the car door and the weather stripping (the rubber seal around the door) - aim for the area near the lock mechanism.
Now use the hanger to feel for the lock rod or button inside the door. This may take some trial and error - and probably quite a lot of time.
Once you’ve hooked the lock rod or button, gently pull or push it to unlock the door. If successful, the door should unlock, and you can get in.
Keyless ignition problems are not uncommon, especially in relation to fobs. If your car uses keyless technology to start, finding out your key fob won’t work is no fun. However, you may be able to get your vehicle going by holding the fob close to the ignition system. The residual current may be enough to start the engine.
Some key fobs also feature a ‘hidden’ or ‘emergency’ physical key, which can be used to start the engine/unlock and lock the doors. Check your owner’s manual for details.
If you find yourself in the unenviable situation of plucking your key fob out of a puddle or the kitchen sink, your options are rather limited. Your one hope is to dry the device out. Placing it in a bag of uncooked rice may help dry it out faster, however, some key fob experts suggest that the starches found in rice may themselves damage the electronics. Putting it in a bowl with silica gel sachets could be more effective.
If you don’t have silica to hand, placing it in a warm, dry room for a few days could also help.
All that said, water is the arch enemy of circuit boards and chips, so you may have to replace the key fob altogether. Even if it does work, its lifespan (or that of its battery) may have been shortened.
