A system includes a wearable device that receives, via a wireless transceiver on the wearable device, a code from a wireless ignition device of a vehicle. The code is usable to start or stop an engine of the vehicle. One or more sensors on the wearable device detect a gesture performed by a user wearing the wearable device. Responsive to detecting the gesture, the wireless transceiver transmits the code to start or stop the engine of the vehicle to the wireless ignition device effective to cause the ignition device to start or stop the engine of the vehicle.