What to do if you lose your key fob

It can be costly to replace, though it’s sometimes possible to program a new one yourself to save some cash

One of the handiest features offered on new vehicles these days is without question, a keyless entry system. It’s a true convenience to be able to walk up to a car – especially while carrying an armload of packages – and unlock it (or open the trunk or hatchback) by simply pressing a button. Most include a panic alarm that engages the vehicle’s horn to ward off potential attackers or to help find the car in a crowded parking lot.

Depending on the model, the transmitter can either be attached to a key or exist as a separate device. Newer systems enable a motorist to enter and start a vehicle while simply carrying the key fob in a pocket or purse.

Unfortunately, replacing one that’s lost or broken can be a costly proposition, and it’s far more complicated than only going to the hardware store and having a new key made. Today’s keyless access devices not only require you to purchase a new remote but to also have it programmed to work with your particular vehicle.

If your car is still under warranty and the remote breaks, you’ll probably be able to obtain a replacement from a dealer free of charge. Likewise, there’s a chance your car’s auto insurance policy or roadside assistance program covers lost or damaged keyless-entry fobs.

Depending on what you drive, a new transmitter can cost anywhere from $50 to $400. If you buy a replacement from a locksmith or a dealer’s service department and have them program it for you, you’ll pay full price for the unit as well as labor costs, which can run another $50 to $100.

But you can save money by shopping around to find the lowest price on a new remote and, if possible, program it yourself. However, if the remote is incorporated into a key, you’ll also have to get it cut. If you don’t have a spare key that can be used as a guide, you’ll have to go to a dealership to have a new one made.

You can usually find generic replacement remotes at hardware and auto parts stores, though not all units work with all vehicles. You’re more likely to find a suitable aftermarket replacement if you’re driving an older vehicle, say a 2009 or earlier model, that relies on less-complex technology than newer cars. The best way to go is to purchase an original equipment (OEM) replacement key fob. You’ll find several internet retailers that sell OEM key fobs and remote entry keys at far lower prices than dealerships will charge.

At that, you may not be able to program a new unit at home, depending on the vehicle. European brands, in particular, include special security chips and encryption codes in their devices that require programming to be performed at a dealership. Some internet vendors we checked do not sell replacement units for either Audi, BMW, Mercedes-Benz or Volkswagen vehicles. The ones we checked that do offer replacements for late-model

vehicles from those brands make it clear that they require professional programming.

Where a do-it-yourself setup is possible, the procedure varies from one make and model to another. Some automakers provide programming instructions in their owner’s manuals, and you can find information for many vehicles on the internet. The catch is you may need two working key fobs to expedite the procedure or perform it at all. That means it’s prudent to buy and program an extra remote before you need it.

This may seem obvious to some, but if you still have the keyless transmitter and it’s malfunctioning, you might want to check the battery before taking the time, expense and effort replacing it.