Nissan Motor, DoCoMo and Sharp have jointly developed a mobile phone able to function as an intelligent key for cars.
The device will incorporate Nissan's Intelligent Key system, already a standard feature in various Nissan vehicles, the firms said.
Nissan's Intelligent Key system has been installed in more than 950,000 Nissan models since 2002. It employs two-way wireless technology to automatically unlock and lock the car door and starts and stops the engine.
Nissan and Sharp have now integrated these capabilities into the new handset.