Many deals include a bypass-module installation, but some do not. If this deal does not cover a bypass-module installation and your car needs one, then there could be additional costs. Learn more in our guide to remote car starters.

The Deal

• $186 for a MESA 4405M remote car starter with bypass module and installation ($400 value)

Remote Car Starters: The Key to Keyless Ignition

Remote car starters are as easy to use as TV remotes, but the technology that turns over your engine without turning any keys isn’t quite as simple. Read on to learn what’s behind this automotive wizardry.

From a technological standpoint, remote car starters function much like another popular, if criminal, mode of keyless ignition: hot-wiring. By now, the image is familiar from action films. A thief busts open the panel under the steering wheel, examines a tangle of multicolored wires, and rubs the correct ends together to bring the engine to life. This sequence sends a current through the ignition wire, initiating the engine’s activation process, which would otherwise be triggered by the act of turning the key.

Remote car starters circumvent the need for keys by activating the same electronic cycle, but rather than joining frayed wires, they use a module that conjoins the wires beneath the panel. The module communicates with a radio-equipped remote control that, when pressed, tells it to send an electric current through the ignition wire, thus starting the car. Most standard car starters only communicate with the engine, though some advanced models can connect to other systems to unlock the doors or adjust the heat and air conditioning inside your car.

To prevent hot-wiring, most modern vehicles have built-in immobilizers, electronic security devices that prevent the car from starting if they do not detect the radiofrequency identification code broadcast by a microcircuit inside the key. To overcome this hurdle, most remote car starters include a bypass module, a computer chip that is uniquely programmed to communicate with the vehicle in which the starter is installed. Bypass modules make car starters feasible to install in just about any car, so owners can warm their engine up before entering the car on an icy morning or give the air conditioning a head start if it’s been parked for a long time in a volcano.