What push to start ignition does
Push to start is an ignition system that lets you start your car by pressing a button instead of turning a key. The button is usually located on the dashboard near the steering wheel. When you press it, the car's computer reads a signal from a key fob in your pocket or bag and starts the engine if everything checks out.
The system works because your key fob transmits a unique code that the car recognizes. You don't need to insert anything or turn anything — just have the fob with you, press the brake pedal, and press the start button. The car verifies the fob's signal before cranking the engine.
Push to start has become standard on most new vehicles sold in the last ten years. It's faster than using a key, and it means you can't accidentally leave your keys in the ignition. However, it also means your car won't start if the battery in your fob dies or if the car's receiver can't detect the fob signal.
Key Takeaways
- Push to start requires both a working key fob battery and a functioning receiver in your car to detect the fob's signal.
- If your car won't start, check whether the fob battery is dead by testing the fob's lights or locks — they use the same battery.
- You can usually start the car with a dead fob by holding it against the start button or placing it near the steering column, depending on your car's design.
- If the car still won't start and the fob battery is good, the problem is likely in the car's receiver or electrical system, and you'll need a mechanic or dealer.
- Replacing a fob battery costs five to fifteen dollars and takes two minutes; a new fob from a dealer costs fifty to four hundred dollars depending on the car.
How to tell if your key fob battery is dead
The first step when push to start fails is to check whether the fob battery is the problem. Your key fob battery powers the lock and unlock buttons as well as the start signal, so if those buttons don't work, the battery is dead.
Press the lock button on your fob while standing near your car. If the car locks and you hear the locks click, the battery is fine. If nothing happens, the battery is dead. You can also test the unlock button the same way. Some fobs have a light that comes on when you press a button — if that light doesn't work, the battery is dead.
A dead fob battery is the most common reason push to start fails, and it's also the easiest to fix. Most fob batteries last three to four years depending on how often you use the fob. Once the battery dies, the fob won't transmit any signal to the car, so the car can't verify it's you and won't start.
Replacing the key fob battery yourself
You can replace a fob battery without going to a dealer. First, look for a seam or slot on the edge of your fob — most fobs have a small notch where you can pry the case open. Use a coin or a small flathead screwdriver to gently pry the two halves apart. Don't force it; if you can't find the seam, check your car's manual for the exact location.
Once the fob is open, note which side the battery is on and which direction it's facing (the positive or negative side up). Take a photo with your phone so you remember. Remove the old battery and take it to an auto parts store, pharmacy, or grocery store — the staff can tell you the battery type number, usually something like CR2032 or CR2025.
Buy a replacement battery of the same type. They cost three to eight dollars. Insert the new battery in the same direction the old one was facing, snap the fob case back together, and test the lock button. If the lock works, the fob is working again and you can try starting the car.
Starting the car with a dead fob battery
If your fob battery is dead and you need to start the car right now, most vehicles have a backup method. The most common approach is to hold the fob directly against the start button while you press it. Some cars require you to hold the fob against a specific spot on the steering column or dashboard — check your owner's manual for the exact location.
The reason this works is that holding the fob very close to the button reduces the distance the signal has to travel, making it strong enough for the car to detect even with a weak battery. This is a temporary solution only — it won't work reliably for long, and you should replace the fob battery as soon as you can.
If holding the fob against the button doesn't work, some cars have a physical key hidden inside the fob. Look for a small slot or button on the fob case that releases a metal key. You can use this key to unlock the driver's door, and then you may be able to start the car using an ignition slot hidden under a panel on the dashboard. Not all cars have this feature — again, your manual will tell you.
When the fob battery is fine but the car still won't start
If your fob battery is working (the lock and unlock buttons work) but the car won't start when you press the button, the problem is in the car itself, not the fob. The most common causes are a dead car battery, a faulty start button, or a problem with the car's receiver that detects the fob signal.
Check whether your car's dashboard lights come on when you press the start button. If the lights come on but the engine doesn't crank, the car battery is probably fine and the problem is the start button or the receiver. If the lights don't come on at all, the car battery is dead — you'll need to jump-start the car or charge the battery.
If the car battery is charged and the dashboard lights work but the engine still won't crank, you need a mechanic or a dealer. The start button itself may be broken, the receiver may not be detecting the fob signal, or there may be a problem with the car's electrical system that prevents the starter motor from turning on. These are not repairs you can do yourself.
Getting a replacement key fob
If your fob is lost, stolen, or broken beyond repair, you'll need a new one. You have two main options: buy from a dealer or buy from a third-party seller.
A dealer fob is programmed to your car and is may provide to work, but it's expensive — typically fifty to four hundred dollars depending on the car brand and model. Luxury cars and newer models cost more. The dealer will program it while you wait, usually in under an hour. If you have only one fob and it's broken, the dealer is your safest choice because they can verify the car's ownership and make sure the new fob is legitimate.
Third-party fobs from online retailers or auto parts stores cost fifteen to eighty dollars, but they require programming. Some auto parts stores will program a third-party fob for free or for a small fee if you buy it from them. Others won't program fobs they didn't sell. You'll need to call ahead and ask. If you program it yourself, you'll follow a sequence of button presses and key turns described in your owner's manual — the process varies widely by car brand.
Preventing fob problems
Replace your fob battery every three to four years, even if it's still working. This prevents you from being stranded with a dead fob. Mark the date on your calendar when you replace it so you remember when the next replacement is due.
Keep your fob away from water, extreme heat, and physical damage. Fobs are water-resistant but not waterproof — if you drop it in water, dry it completely before using it. Don't leave it in a hot car or in direct sunlight for long periods, as heat can damage the battery and the circuit board inside.
If you have only one fob, consider getting a spare made by a dealer or a locksmith. A spare costs less than a replacement and gives you a backup if your main fob fails. Keep the spare in a safe place at home, not in your car.
Frequently Asked Questions
Can I start my car if I lose my key fob?
If your fob is lost and the battery is dead, you can't start the car using the push to start button. However, most cars have a physical key hidden in the fob case that you can use to unlock the door. Once inside, check under the steering column or dashboard for a hidden ignition slot where you can insert the key and start the car manually. Not all cars have this feature — consult your manual.
How long does a key fob battery last?
Most fob batteries last three to four years with normal use. Heavy users who lock and unlock their car many times per day may see batteries die sooner. Batteries left unused in a drawer can last longer. There's no way to predict exactly when yours will die, so replacing it every three years is a safe approach.
What does it mean if the start button flashes or blinks?
A flashing start button usually means the car's receiver isn't detecting your fob signal. Try holding the fob closer to the button or the steering column. If that doesn't work, the fob battery may be weak even if the lock buttons still work — try replacing it. If a new battery doesn't help, the car's receiver may be faulty and you'll need a dealer to diagnose it.
Can a locksmith program a key fob?
Yes, many locksmiths can program a fob, but not all of them. Call ahead and ask whether they program fobs for your car brand — some locksmiths specialize in certain brands or older vehicles. Locksmiths are usually cheaper than dealers but may take longer to get an appointment. If you need a fob when ready, a dealer is faster.
Is push to start less reliable than a traditional key?
Push to start is reliable when the fob battery is good and the car's receiver is working. The main weakness is that a dead fob battery leaves you stranded if you don't know about the backup methods. A traditional key can't fail in the same way, but it can be lost or broken. Most drivers find push to start more convenient once they understand how to handle a dead fob battery.