Your Car’s Keyfob Battery Is Dead? What Now?

Most drivers have perhaps been here before.

Initial signs of a shorter unlocking distance from your car, perhaps the car doesn’t detect the key as easily as it once did.  You would have thought, maybe it’s about time to change the keyfob battery – but, amongst the lot of things you do every day, it’s at the back of your mind – or maybe you thought, you’ll change it when you send your car in for its next service.

Either way, it doesn't happen, and you’re now stuck outside your car with bags in your hand, and that darned door just refuses to unlock.

Now, for older cars, this isn’t so much a problem. Simply use the mechanical key, open the door, and get in. This might trigger the alarm but more often than not, alarm systems will have an override button to temporarily shut off the alarm, so you can start the car. Batteries for older car keys (such as the A27 dry-cell, or CR2025 coin cell) are also much easier to find and replace – with most hardware or electronic stores retailing them.

Newer cars, however, will have more specific coin-cell batteries and/or battery capacities depending on make and model, which makes it all that more important that keyfobs for newer generation cars be replaced on a timely basis.

This as you can imagine, becomes a bit trickier with new vehicles with Keyless Entry and Start/Stop systems. What do you do when your car key, doesn’t even look like a key!

Well, the first thing to do is not to panic, because your car manufacturer has already thought of this, and engineered certain redundancies into your car’s security systems for situations such as this.

Just follow this step-by-step guide to get yourself home:

• Firstly, double-check if the keyfob battery is really dead. Yes, the battery might be on its way out, but maybe it’s got just enough charge for one more unlock. So get the key near the car handle for the car to detect the key. If that doesn’t work, maybe you can try waving the key just above the windscreen on the driver’s side door handle. Assuming there’s just enough charge in the key and the car picks it up, you’re good to go.

• If that doesn’t work. You now have to bypass the Keyless entry system and use a mechanical key to enter the car. It’s important to note that different manufacturers will have different keyfob designs and slightly different methods to enter and restart your car in cases like this, so we can’t stress hard enough: understand your car’s systems. Read the car’s manual, ask your service advisor or mechanic, or if in a pinch, go on YouTube and check out what to do. There’s a wealth of information on YouTube on practically any car model – new and old.
   
• What you want to do next is find the mechanical key, which normally is designed into the keyfob – look closely for what might seem like a clip/lock mechanism. In some cases it might not be a lock at all, you might simply have to pull the key out of the key fob and you’re good to go.
   
• With the key in hand, simply look for the traditional keyhole on your car’s door/handle and unlock your car. Now you are in!

• Now, here’s where the steps may differ depending on the cars make and model. For BMWs you have to hold your key next to steering wheel console (usually located near the Start/Stop button) while pressing the start button, for certain Mercedes-Benz models, you have to plug out the Start/Stop button which reveals a key slot. In the case of Honda or Toyota models, once you’re in the car, place your key fob right up against the Start/Stop button and push to start. Or you can even use the keyfob itself to push the Start/Stop button.

For the simplest how-to video, check out our video below on how we unlocked and started a Toyota Hilux with a dead keyfob battery.

We hope we've managed to shed some light on what to do if your keyfob runs out of juice. Remember don't panic, go on Carlist, read this informative article and you'll soon be on your merry way. 

However, replacing your car's key need not be such a mind-numbing affair, you can actually check out The Car Key Man YouTube channel, which shows you how to change the keyfob batteries for a plethora of different makes and models.