How a Keyless Push-Button Ignition Works

Technology has advanced for automotive security and user-focused features, and a shift is occurring where traditional key-and-cylinder starting systems are being replaced by keyless push-button ignition systems. They are incredibly simple to operate and provide excellent security.

The system was developed initially in the mid-1990’s by Siemens and was released first in Mercedes-Benz vehicles as Keyless Go. Since then, their popularity has grown exponentially. Now, keyless push-button ignition systems are known by dozens of different names depending on the auto manufacturer, including:

  • SMART Key
  • Keyless Go
  • FAST Key
  • Intelligent Key
  • Comfort Access

How it Works

Keyless push-button ignition operates based on low-frequency radio ID. Your key fob is a transmitter equipped with a specific electronic ID tag and the signal is amplified with a battery in the key fob. When you are in close proximity to your vehicle, antennas around your vehicle recognize your key fob’s presence and allow you to unlock and lock your doors with the press of a button on the handle, if it is so equipped.

When you enter your car, the antennas around your vehicle make comparative calculations to determine that you are indeed inside. The antennas transmit the electronic ID from the key fob to the receiver module. When you press the ignition button to start the car, the receiver disables the immobilizer, powers the starter circuit, and the engine turns over.

If the key fob battery is dead, you may not be able to unlock your doors or start your car in the same fashion. Manufacturers typically include a backup source to start your car such as a key shaft hidden in the fob. There is a location in the dash it needs to be inserted where another antenna or transponder ring picks up the diminished signal and allows the car to start.

If you lose your key fob, your car will not be able to start at all. You will need to have a new key made in order to use your car again.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

What Does the Ignition Switch Warning Light Mean?
The ignition switch warning light could mean there's an issue with the ignition system or the car key. It could be due to a glitch or worn out key.
How to Replace an Ignition Ignitor
The ignition ignitor sends a signal to supply power and start the engine. A common sign of failure is a disruption in the engine's starting process.
How to Replace Ignition Cables (Spark Plug Wires) in Your Car
The ignition cable, or spark plug wire, carries a signal from your vehicle’s computer to the spark plugs. This is crucial to the ignition system.

Related questions

How do I lock the doors from outside without a key?
The doors can be locked even if you don’t have a key. Just switch the inside Lock button into the lock position before you close the door. This allows you to lock all of the doors at once even if...
How do I replace the remote keyless entry (RKE) transmitter battery of a 2012 Chevrolet Equinox?
The remote keyless entry (RKE) transmitter gets a lot of use, as it helps you lock and unlock your vehicle with regularity. As a result, the battery can sometimes die. You can replace the battery in the RKE transmitter yourself:...
Trouble starting when cold or damp outside.
This sounds like a possible battery problem. Batteries do not perform as well in colder temperatures. Batteries have a rating for starting power measured in cold cranking amps (CCA). I would recommend having your battery load tested (https://www.yourmechanic.com/services/battery-is-dead-inspection) by a...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com