FRANKFURT -- Volkswagen said software problems that affected the launch of its new Golf are now also a "challenge" with the ID3 battery-powered hatchback, which is due to go on sale in Europe in the summer

German business monthly Manager Magazin reported last month that setbacks meant over 20,000 ID3 cars would be built without a full software suite, requiring teams of engineers to manually fix the problem post-production at additional cost.

"Establishing a powerful new electronics and software architecture is a challenge that can lead to difficulties or delays, which we are currently addressing," a VW spokesman said. "The time plan remains in place: market launch is scheduled for summer 2020."

The latest generation Golf, whose roll out across Europe was delayed to the first quarter, contains around 100 million lines of code with the infotainment system alone accounting for roughly a fifth of that. By comparison, a car built in 2010 had a tenth of the complexity, according to VW.

Whereas the Golf is only equipped with an evolutionary CAN FD electric-electronic (E/E) architecture, the ID3 is the first model to receive the new E3 platform for the fastest possible data transfer rates.

VW Group CEO Herbert Diess has said he will need full availability of the ID3 from launch in order to ensure stringent new European fleet emission targets can be met without the need to pay potentially hundreds of millions, if not billions, of euros in fines.

VW started series production of the ID3 in November. It is using the subsequent months until delivery of the first cars to continue fixing any issues that may come up during further field testing.

ID3 cars coming off the production line are being stored in hired parking lots until the software is installed, Manager Magazin said.

The VW spokesman said the company aims to build about 100,000 electric cars this year in its plant in Zwickau, Germany.

Software glitches that marred the Golf's development have prompted Diess to bundle the group's current software expertise and carve it out into a new independent subsidiary called Car.Software, founded at the start of this year.

By 2025, more than 10,000 digital experts are expected to develop the software for both vehicles and digital ecosystems, as well as customer-centric functions at dealers.