Tesla will test the production lines for the upgrade during From Sept. 19 to Nov. 30, the statement added.
Reuters previously reported Tesla had been ramping up its output to reach a target of producing around 22,000 units of Model 3 and Model Y cars per week at the Shanghai plant.
Tesla did not respond to a Reuters request for comment.
The US automaker planned to invest up to 1.2 billion yuan ($170 million) to expand production capacity at its Shanghai factory that would allow it to employ 4,000 more people at the site, state-backed Beijing Daily newspaper reported last November.
The project was originally expected to be finished in April, the Chinese media reported then.