Several incidents bedevilled Sydney's new North West Metro on Wednesday including a breakdown, a failure of live transport data and incorrect announcements that train doors were closing on a moving train.

The most severe hiccup on the Metro's fourth day of operations occurred when a driverless train stopped moving between Epping and Cherrybrook after it lost communication with the network's control system about 12.50pm.

Driving a driverless train: A customer journey co-ordinator, left, took control of the train and drove it to Cherrybrook.

A customer journey co-ordinator on board took control of the train and drove it to Cherrybrook.

When the train arrived at Cherrybrook, the doors initially failed to open, Nine News reported, but customers were eventually able to disembark and the faulty train was taken back to the depot at 1.14pm for testing.