Abstract: A portable infrared signal generator is actuatable by a motor vehicle operator at a distance from the vehicle to generate digitally coded infrared signal pulses in accordance with either a first or a second predetermined digital code. A receiver on the motor vehicle is effective to receive the infrared signal pulses, decode them and actuate apparatus responsive to the first digital code to unlock a power door lock and power a light effective to illuminate at least a part of the vehicle or responsive to the second digital code to actuate an alarm. Both the first and second digital codes contain a common identifying portion substantially unique to the particular motor vehicle, which portion may be permanently stored in the generator and receiver by the connections of the input/output terminals of a microprocessor chip mounted on a printed circuit board to one of two voltage sources on the printed circuit board.