Smart keys, explained — push-button start and what happens when it stops

How a smart key works

A smart key contains a battery-powered radio transmitter (unlike a transponder chip, which is passive). When it is within a few feet of the car, it exchanges a rolling cryptographic code with the vehicle. If the code is valid, the car allows unlock-on-touch and push-button start.

The rolling code changes each time — you cannot record and replay one. This is what makes smart keys much harder to defeat with signal-capture theft attempts than early keyless entry systems.

Inside every smart key there is also a small mechanical “valet” key that lets you unlock the door if the fob battery dies, and a passive transponder chip that lets you start the car by holding the fob against the ignition button.

What breaks

The three common smart key problems in Kenner

• Battery dying. By far the most common. Symptoms: intermittent unlock, longer range problems, warning light on dash. Fix: CR2032 battery ($3), 2 minutes. Do not go to the dealer for this.
• Button contacts corroding from humidity. Kenner-specific. Buttons feel spongy, then stop responding one at a time. Fix: clean and reseal ($75 to $135), or replace fob if too far gone.
• Key lost entirely. Fix: originate from VIN, program on site, delete lost key from car memory ($395 to $625). This last step matters — whoever finds the lost fob cannot start the car once we have deleted it.

What we do when you lose a smart key entirely

This is the “all keys lost” scenario — most common after airport travel where the fob was on your keyring and now is not.

• Open the door without damage — air wedge and long-reach tool.
• Verify ownership — registration in the glovebox, ID.
• Cut the emergency valet blade — takes 3 minutes on our equipment.
• Program the new fob to the vehicle — 20 to 45 minutes depending on manufacturer wait time.
• Delete the lost fob from vehicle memory — 5 minutes, non-negotiable step.

Total time on site: usually 45 to 75 minutes. Total price: $395 to $625 depending on the vehicle. No tow required.

The MSY factor

If you are landing at MSY and realise your car key is not with you, ring us before anything else. We are 15 to 25 minutes from any lot at the airport and this is a locksmith job, not a tow. Full details on the MSY guide.

Questions

Smart key questions

What is a smart key?

A car key with active radio circuitry (batteries and a transmitter) that broadcasts your identity to the car whenever it is close. The car recognises it in your pocket, unlocks when you touch the handle, and starts with a push button on the dash. No physical key insertion.

How do I know if I have a smart key?

If your car has push-button start and you never insert a key, it is a smart key. Usually a chunky plastic fob with a mechanical valet key hidden inside as backup.

Why is a smart key replacement so expensive?

Three reasons. The key itself contains active radio circuitry that costs more to manufacture. The pairing procedure is longer — many vehicles enforce a 15 to 30 minute security wait time to prevent theft-by-programming. The equipment to program smart keys is more specialised.

How much for a smart key replacement in Kenner?

$200 to $495 for a duplicate with an existing working key. $395 to $625 all keys lost. Both prices include cut of the emergency valet key and full programming on site.

What is the emergency valet key inside the fob?

A small mechanical key hidden inside the smart fob for two situations: unlocking the driver’s door if the fob battery dies, and starting the car via a hidden slot near the ignition button. We cut it as part of any smart key job.

My smart key battery is dead but I still need to drive. Now what?

You can still get in and start the car. First, use the mechanical valet key inside the fob to unlock the door. Second, hold the fob against the start button (there is an inductive coil that will read the fob at close range). The car will start. Then replace the fob battery — CR2032 in most models, $3 at any pharmacy.

If I lose one of my two smart keys should I get another one made?

Yes. Losing one of two means the lost fob is still active on the car until you have it de-programmed. Whoever finds it can potentially unlock and start your car. We recommend re-programming the car to accept only your remaining key (removing the lost key from memory) plus cutting a new spare. $195 to $325 done on site.