The Deutsche Bahn Class 423 EMU is a light-weight articulated electric railcar for S-Bahn commuter networks in Germany.

The train has similar dimensions to its predecessor, the Class 420 EMU, but is significantly lighter and has one large passenger compartment, while that of the 420 is divided into three parts.

A Class 423 unit consists of four cars that share three jacobs bogies and can only be separated at maintenance facilities.

Different consists usually occur when the remains of partially destroyed units are combined to form one intact EMU.

In 2007, however, this procedure was temporarily taken out of service until light grids were retrofitted over almost the entire height of the boarding area.

The original pushbuttons, which had a pressure surface the size of a thumb, only provided visual feedback on contact.

In the course of modernization, the vehicles were fitted with pushbuttons with a larger pressure surface, an illuminated ring and audible and perceptible actuation.

The multiple units are powered by eight four-pole, water-cooled three-phase asynchronous traction motors with a total output of 2350 kilowatts.