How Close Does Key Fob Need To Be To Start Car?

The keyless ignition system is an increasingly popular car feature. This function lets you start your car without searching for a key in your pocket or handbag. But how close should your key fob be to start your vehicle? We researched this question and here is what we learned. 

In most circumstances, the key fob needs to be inside the vehicle to start the engine.  Moreover, safeguards are built into keyless ignition systems to prevent your vehicle from starting at an unexpected time. 

Stay with us as we cover how the keyless ignition system works, what benefits you might enjoy, and what dangers it may impose. In addition, we'll also discuss the different types of keyless ignition systems and what to do in case you have a dead key fob. 

Man holding a keyfob near to blue car, How Close Does Key Fob Need To Be To Start Car?

How Does A Keyless Ignition System Work?

The fob that comes with keyless ignition systems can be kept in your pocket, handbag, briefcase, or anywhere close to the receiver within the vehicle.

The fob sends a distinct low-frequency signal to the car's computer network, which verifies that the signal was transmitted correctly and allows you to start the engine by pressing a button on the dashboard or console. It's just as simple to turn off the motor: simply push the start/stop button.

In addition to keyless ignition, most systems provide keyless entry, which allows you to enter the vehicle without having to insert a key or press a button on the fob.

You can watch this video to understand more about keyless ignition: 

What Are The Types Of Keyless Ignition Systems?

The keyless ignition system differs from one manufacturer to the next. However, these systems function similarly. The following are some of the common ignition switches:

  • Push-Button Start
  • Smart Key
  • Rotary Switch
  • Rocker Type

Push-Button Start

Car stop start system with finger pressing the button

The most prevalent keyless ignition type in cars is the push start button. It disarms and starts the car with a key fob. The car will only start if the key fob is within range when you press the engine start button.

After getting into the car, step on the brake and then push and keep holding the start/stop button until your engine starts. To switch off your automobile, make sure it is in parked gear, then press the start/stop button until it completely shuts off. You should also use the parking brake.

Smart Key 

Man holding a keyfob near to blue car

It is the most recent version of the key fob. Within a 5 to 10-foot range, the ignition system can detect key fobs and exclude commands for disarming. The drivers can get inside the vehicle and start it right away.

Smart keys can also be utilized for a variety of additional tasks, such as remotely controlling a climate control system.

Rotary Switch

Car AC Air Conditioner Mode Selector

These are the traditional ignition systems that require rotation to start and stop the engine.


Turning the engine on and off requires flipping the spring-loaded rocker switches.

What Are The Benefits Of Keyless Ignition Systems?

The most significant advantage of keyless ignitions is increased driving convenience. Moreover, the key fob and ignition's unique security code prevents car theft.

Another advantage of having a keyless system is the variety of driver comfort elements that can be managed remotely. It also reduces car accidents by not starting the engine until the brake pedals are pressed.

A key fob also reduces the possibility of key misplacement or having to scour the depths of your pockets or pocketbook for the keys.

What Are The Dangers Of Keyless Ignition Systems?

On the downside of things, the radio frequencies transmitted by the key fob can be traced and exploited to break into automobile systems. Also, without the fob, the system is inoperable.

As with any electrical component, it wears down with time to the point that you must replace the entire key fob or fix the complete system. Just to be able to start your car again can be an expensive buy.

Another issue is that a technological problem may cause the automobile to fail to recognize the presence of the key fob. In that instance, the vehicle will not start or the engine may lose power.

Here are some safety concerns a keyless ignition system may impose:

  • The combination of keyless ignition and automated stop/start raises the possibility of drivers mistakenly leaving their vehicles running. When this occurs in a garage, you are at risk of carbon monoxide poisoning. 
  • Drivers who do not know how to turn off their vehicles' engines in the event of an on-road emergency.
  • Drivers who turn off their vehicles without placing them in "park" and walk away from them, leaving them vulnerable to rolling away — into another car or a person.

How Far Can You Drive Without A Key Fob?

If your car gets stolen or you accidentally dropped your key fob, you may wonder, will your car stop or will it still run? 

To answer that, here are some famous vehicle manufacturers and how far their cars can go without a key fob: 

  • Audi- 8 to 10 miles
  • Acura- 10 miles/ approximately 20 minutes
  • Jeep- 15 minutes
  • Mercedes- 20 minutes

Although, most car manufacturers allow cars to be driven without limit even if the key fob is not with them. Here are some of those brands: 

  • BMW
  • Chevy
  • Honda
  • Dodge
  • Ford
  • Toyota
  • Nissan
  • Hyundai
  • Lexus
  • Mazda
  • Volkswagen
  • Volvo

How Much Does It Cost To Replace A Key Fob?

Remote controled car key

If you lost your key fob, replacement fobs can cost somewhere between $250-$600 including the labor for the programming. 

But if your fob just ran out of battery, it will only cost you less. Batteries for key fobs typically cost $10 or less, though some fobs require two. Because it simply takes a minute or two, battery specialist shops and dealers frequently replace the batteries for free.

You can read more about the cost of replacing keyless entry fobs in this article: How Much Do Keyless Entry Keys Cost? [What You Need To Know].

What To Do When The Key Fob Runs Out Of Battery?

Automatic door key fob or smart car key

In most cars, the technology is designed to work with a remote that has a low battery or is completely dead. Of course, the precise method for using a dead key fob will vary depending on your car's model, so you need to consult your manual for details.

If you have a dead fob, here is what you can do to start your car: 

  1. On the rear of your fob, look for a little sliding button. Slide or click the button to release the key fob cover. To get it to release, you may need to use your fingernail and a little force.
  2. Once you've obtained the mechanical key, use it to unlock the door. If you don't see a key slot, it's most likely hidden beneath the handle cover.
  3. To access the key slot, carefully pop off the handle cover with the key.
  4. Close the key fob and replace the mechanical key.
  5. Push the START button with the key fob. Instead of pressing the button with your finger, push the key fob against it. Many manufacturers utilize this as a backup device to ensure that the car can start even if the fob is dead.
  6. Some vehicles include a secret key fob slot that allows you to start the engine. The slot is the ideal size for your fob. Insert the dead key fob into the slot, then use the push-button start as usual.

What Are The Signs That Your Key Fob Needs Battery Replacement?

Even though your key fob appears to be functioning normally, slight anomalies can develop when your battery is nearing the end of its life. You're probably coping with these problems without even recognizing them.

However, these minor inconveniences may gradually lead to more catastrophic repercussions:

  • The signal range of a common fob is between 30 and 60 feet. However, if your remote's battery runs out, it will reduce the range of your fob's operation.
  • You may need to press the button on your fob numerous times before your vehicle recognizes the signal. When this happens, your battery struggles to generate enough power to operate. If this is the case with your key fob, you should replace the battery as soon as possible.
  • Some key fobs are merely used to unlock doors, while others are necessary to start push-to-start engines. It's possible that your key fob is to blame if this component is likewise inconsistent and requires repeated presses.
  • Although you may only have to click the button once, there is a considerable one or two-second delay before hearing your car unlock. This is also a sign that the battery in your key fob is dying.

Final Thoughts

Man holding a keyfob near to blue car

Now that we live in a time when convenience reigns supreme, it will only be a matter of time before all cars will shift to keyless ignition systems. 

For the car to start, the key fob needs to be inside your vehicle. Also, since most keyless cars are powered by push-button ignition, you need to step on the break to power the car. 

If you enjoyed this article, be sure to check out these great posts:

What SUVs Have Keyless Entry?

How To Test Keyless Entry Remote.

Share this article

Leave a Reply

Your email address will not be published. Required fields are marked *