An intake air heating system for a vehicle includes an electrical switching device configured to selectively connect a battery of the vehicle to a heater coil in contact with intake air of the vehicle. The intake air heating system includes a control circuit configured to, in response to an enable signal from an engine controller, drive the electrical switching device to connect the battery to the heater coil at full current. The control circuit is configured to measure a resistance of the heater coil indicative of an initial temperature of the heater coil and, in response to an estimated temperature of the heater coil exceeding a desired temperature value, modulate the electrical switching device to reduce current from the battery of the vehicle to the heater coil.