The executive leading Apple Inc.’s development of an electric car is leaving the company, according to two people familiar with the move.

Steve Zadesky, who was tapped by Chief Executive Officer Tim Cook to shepherd Apple’s bid to enter the automobile market, stepped down for personal reasons, not because of his performance, said one of the people, who asked not to be identified discussing Apple personnel matters.

The leadership change hasn’t altered Apple’s plans to develop a car, one of the people said. Zadesky’s exit was reported earlier by the Wall Street Journal. Apple declined to comment.

While Apple has never confirmed it’s developing a car, the iPhone maker has been building a team, including engineers and experts in battery and robotics technology, to work on the project. The Cupertino, California-based company last year had been exploring whether it could go into production by 2020, though such deadlines are fluid in automotive design. Zadesky, who earlier worked on the iPhone and iPod, had been leading the effort since 2014.

According to the Journal, Apple’s team has run into trouble in development, with some suggesting the deadlines aren’t obtainable.