Plans for an extension southeast towards Rodrigo de Araya were postponed after a major earthquake in 1985; in fact, only two stations opened separately at the line's northern end in 1987 (Santa Ana and Puente Cal y Canto).

Two decades later, with a change of plans, it was decided that Line 2 would continue northwards instead of southeast, owing to recent availability of Tunnel Boring Machines, and on September 8, 2004, two further stations opened to the north, Patronato and Cerro Blanco.

These stations marked a new feat in Santiago and overall Chilean engineering by building under the Mapocho River and the Costanera Norte freeway.

On October 26, 2009, the express service began to run on Line 2, stopping at certain stations only at peak times, allowing for faster journeys.

Service on the line was partly restored on October 25 with trains running express between La Cisterna and Zapadores.