Performance of the modules for layer 1 of the CMS phase 1 pixel detector upgrade

The instantaneous luminosity of the Large Hadron Collider will increase to up to 2x10$^{34}$\;cm$^{-2}$s$^{-1}$ by 2023. In order to cope with such luminosities, the pixel detector of the CMS experiment has been replaced in January 2017. The upgraded detector features four sensitive layers in the barrel part. A designated readout chip (PROC600V2) is used for layer 1, which is closest to the interaction point and therefore has to handle larger particle fluxes. An irradiation campaign has been performed with PROC600V2 to verify its radiation tolerance up to the maximum expected dose for 2017 of 0.2\;MGy. Modules for layer 1 have been built with PROC600V2 for the detector production. The quality of every inserted module was assessed in a number of tests, some of which were performed using X-radiation. The characteristics of the modules used in the detector as well as the main failure modes will be presented.