Keyless automotive fob stopped working? How to realize entry with hidden function

  • Problems with remote locking fobs are increasingly common for motorists 

Keyless fobs might offer convenience to car owners by locking and unlocking and doors and starting the engine at the push of a button, but when the battery inside them dies it can leave drivers feeling stranded with little option but to call for help.

And problems with keyless fobs appear to be increasingly common for motorists, as technology has shifted the market away from the traditional metal key and lock.

In fact, online searches for ‘why is my key fob not working?’ have increased by 100 per cent over the last 12 months, while TikTok has some 30 million videos relating to ‘how to start my car if my fob is dead’.

With temperatures plummeting in recent days, Auto Trader warns that keyless fob issues are likely to be more common at as winter draws in.

This is because cold weather can take a toll on the battery inside them and shorten their lifespan.

We explain how you can gain entry to your car using a hidden feature in a dead key fob – and the measures you can take to avoid being locked out of your car because of a dud remote key.

Online searches for ‘why is my key fob not working?’ have increased by 100% over the last 12 months, according to Auto Trader. Here’s our guide to resolving the issue

My key fob isn’t working – how do I get into my car?

Because most new car models have a battery-operated fobs and no metal key to unlock the doors and start the engine, issues trigerred by dead batteries are becoming a growing inconvenience.

However, there is a very easy way around the problem that many vehicle owners simply aren’t aware of.

That’s because car makers have provided a built-in solution to this problem that – unless you’ve read the vehicle’s owner’s manual – you might not know about.

Inside the fob is a hidden physical key, commonly referred to as the ’emergency key’.

In some instances, the key flips out of the plastic module and remains connected, while in others the metal key removes entirely. The trick is to look for any area on the key that can be pulled out, like the ring hooks or a small button.

Slide me

Inside the fob is a hidden physical key, commonly referred to as the ’emergency key’. The trick is to look for any area on the key that can be pulled out, like the ring hooks or a small button

Once you have located the hidden key, the next task is to find the concealed door lock.

This will be on in the driver’s side either under the door handle when you pull it out – or behind a small panel to the left of the door handle that you need to remove. 

You will need to pop this off either using a screwdriver or – in cases where the metal key releases from the fob – the opposite end of the physical key. Once you have removed the plastic cover it will expose the conventional lock behind.

Auto Trader says that, while this provides car owners a solution to get into their motors, they should be very careful when removing the lock cover behind the door handle because it can be easy to scratch the paintwork, causing damage that might require an expensive respray to put right.

It can also cause headaches for those who lease or finance cars, as it might not be considered ‘acceptable’ wear and tear as part of your contract for when you hand the vehicle back – and you therefore could be charged a fee for the damage.

It explained: ‘Drivers should be cautious with using the emergency keys to open their car door as any damages and car scratches might lead to some charges at the end of your lease policy. 

‘Some minor scratches are acceptable under fair wear and tear as long as they don’t expose the primer or bare metal. 

‘No leasing funder expects a car to look brand new when it is returned. If there is considerable damage to your vehicle, contact your leasing company and insurance provider to arrange an approved repair.’

Some manufacturers, such as Land Rover, use a non-traditional key and lock. Instead, a key blade removes from the fob and inserts into a small socket under the door handle to remove the cover to provide access to the main door lock.

You may also need to place the key fob somewhere specific – outlined by the manufacturer in the owner’s manual – to deactivate the alarm if it sounds. 

Can I start a keyless car when the fob battery has died? 

For those with cars featuring keyless start systems, the fob usually has a sensor in it which is not battery powered.

Holding this near the start button on the dashboard or centre console will identify the fob to allow the engine to start. 

Again, owners should revert to their car’s manual to find out the specific procedure to follow. 

Other reasons why your key fob might have stopped working

While a flat key fob battery is the most common reason for why it has stopped working, there are three other potential issues that might be preventing it from operating as it should…

1. The key fob has sustained damage

If the battery in your key fob is healthy but it still doesn’t lock or unlock the doors, it is likely to have sustained damage, usually from being dropped – and especially if it has landed in a puddle.

Tech trouble: A glitch in the system could mean you need to have your key fob reprogrammed by the car manufacturer or a locksmith 

2. The key fob needs to be reprogrammed

Like many different forms of tech, key fobs can suffer gremlins and need to be reprogrammed.

This will require the services of a specialist locksmith or the vehicle manufacturer.

If you need to do this, remember to take your spare key to have that version also updated with the latest information, the RAC recommends.

If the battery in your key fob is dying, you will know as it will likely require a few presses of the button to unlock the doors – or you may not be able to activate the locks from longer distances

3. There’s interference – and it could be from thieves

If your car is parked in a location with a lot of electrical or radio interference, it can sometimes block the key fob’s signal. The only way to resolve this is to try and unlock the vehicle from a different position.

This is only likely to affect older car key fobs with less advanced technology.

However, if you do experience this happening to your newer vehicle, it could be that you’re being targeted by motor thieves.

Using signal jammers is a tactic deployed by criminals, especially in busy car parks. 

Signal blocking is where thieves use a jammer to create a virtual barrier between the key and the vehicle to prevent it from locking when the owner presses the button on the fob

When an owner exits their vehicle, a thief lying in wait nearby can use a signal blocker that prevents the key from communicating with the car’s locking system.

An unassuming motorist might think their doors have locked when they’ve pressed the button on the fob, but the jammer has blocked its connection to the car to provide a clear avenue for criminals to get inside without setting off the alarm.

Drivers are urged to always check their doors have locked by looking for the indicators to flash and listening out for the audible beep each time they leave their vehicle.

While car thefts remain high, drivers are told to check their cars have locked behind them by listening out for the audible beep and looking for the indicators to flash

Five tips to keep key fobs working, especially in winter

1. Replace the battery in advance

The battery inside a key fob will usually be good for anywhere between two and six years, so it’s wise to replace it as soon as it shows signs of running low.

You might notice occasions when the fob takes a number of presses to lock or unlock the doors or it only works when you’re much closer to the vehicle. Both are sign that the battery needs replacing. 

Some brands also have a built-in warning that beeps to let the owner know the battery is low and needs to be changed.

Any remote key fob has a battery inside. Once you’ve unscrewed the unit, you can remove it, check the code and order a replacement, usually for no more than £10

Replace the battery is straightforward. Using a small screwdriver, remove the small screws holding the housing of the fob together. Once unscrewed, you can press the release button to remove the battery.

The battery should display a code that begins with the letters CR. This is the type of battery you will need to purchase.

A new battery usually costs between £5 and £10 and they are available from most hardware stores or online. 

Like other types of battery, make sure you match up the positive and negative polarity.

Before screwing the fob back together, you should press the remote locking button to ensure it works correctly before fiddling with the screws to put the housing back together.

If this does not remedy the issue, you will need to contact your local garage to investigate.

Most modern keyless entry fobs now have a ‘sleep mode’ which stops the key from producing a signal. This keeps it safe from car thieves but also extends the battery life

2. Use your key fob’s ‘sleep mode’

Keyless car crime is a major problem for vehicle owners. Between 60 and 70 per cent of cars stolen in 2023 were keyless models, according to data from Admiral.

This is because organised gangs are using a tactic called the ‘relay attack’ to infiltrate vehicle security systems.

Working in pairs, professional thieves use ‘relay’ boxes – one near your car and the other at your front door or close to your property – to duplicate the signal from the key inside your home and use it to unlock the doors and (if you have keyless ignition) start the engine to drive away undetected. 

Car crime: This graphic shows the four-step explanation for how criminals use relay attacks to steal motors

Criminals usually go in pairs to steal keyless cars. One holds a relay box transmitter and stands next to the vehicle while the other stands close to the house holding a signal amplifier

To tackle this scenario, manufacturers fit key fobs with a ‘sleep mode’ that, when activated, stops the key from producing a signal for thieves to target.

In some cases, this sleep mode will automatically activate when sensors detect a period when the fob hasn’t moved and therefore assumes it is out of use and being stored. However, others require the owner to activate the sleep mode manually. 

This usually requires a sequence of pressing a button twice or holding it down for a number of seconds. You should refer to your car’s owner’s manual to understand how to put your fob into sleep mode.

This mode can also be seen as a low-power mode, as it doesn’t require the battery to provide energy to produce the signal, thus extending its lifespan as well as enhancing the security level. 

Auto Trader says you should keep your keys somewhere warm in your house to extend the life of the battery inside it. However, we suggest finding somewhere that wouldn’t be obvious to a burglar. A kitchen drawer (pictured) would be an easy target for thieves

3. Keep your key fob somewhere warm when not in use

Auto Trader says that the temperature of a battery, whether too hot or too cold, is one of the main contributors to key fob problems. 

Like any other type of battery, when a key fob is exposed to colder temperatures the battery inside loses power due to the slowdown of the chemical reactions required to generate energy.

The car sales platform states that this can reduce the capacity of the battery by 2 to 30 per cent.

Therefore, it is advised that you place your keys in a safe space which is warm to help maintain the life of your battery during winter months. 

‘If your home gets particularly cold, consider placing your keys in an insulated place, such as your clothes drawer,’ it suggests. 

‘Additionally, if you are out and about in particularly cold weather, consider placing your key in a secure pocket near your body to keep the key warm.’

4. Keep spare keys safe, regularly check it works and use the disable function

All cars should come with a spare set of keys.

It is not advised to travel around with both at the same time in case you lose them, or they are stolen.

If you do lose one set, you should always get a replacement to avoid being stuck if the battery in your lone fob runs out – or you lose the second key. 

This can be very expensive, though. A report earlier in the year by This is Money found that the average cost of a new car key is £340 – up 40 per cent in just five years.

This is why it is imperative to always keep your spare someone safe, secure and – most importantly – memorable. 

It should also not be somewhere too obvious – like a kitchen drawer – where burglars would often look if they were to break into your house. 

Before putting the secondary fob in a suitable keep safe, you should check the vehicle’s manual to see if it has a ‘disabled access mode’.

Manufacturers often build these in for when drivers are not going to use the key for a long time – especially the case for spares – and so disables the keyless access function, which in turn can save batter life.

5. Keep your key fobs away from children

It’s a well-known tactic to keep small children occupied – and more importantly quiet – by handing them a set of keys. But your car keys is a definite no-no.

Kids are more likely to drop them causing damage and often place them in their mouth, which again can be terminal for the battery inside.