Kawasaki Heavy Industries C151
The trains were upgraded between 2006 and 2008, mainly to improve the trains' appearances. Most of the important parts for the trains' functioning were not replaced as they were still considered in good condition. However, due to what was considered one of the MRT's worst breakdowns in its history, a second upgrade was planned to replace these important parts, but the Land Transport Authority paused the upgrades as they wanted to replace the trains entirely instead. Currently, only a few trains have these parts replaced.