We back up, Baltimore.

Light rail service will resume Saturday after major mechanical issues related to the ongoing rehabilitation of the aging railcar fleet knocked it out of service for roughly two weeks.

The Maryland Transit Administration will cut shuttle bus service that has ferried passengers between light rail stations since the Dec. 8 shutdown and, as a courtesy to riders, will make light rail service free until Jan. 2.

“I thank our dedicated Maryland Transit Administration employees and our contractor’s workforce for all they’ve done to advance these reviews while maintaining safety as our highest priority,” Maryland Transportation Secretary Paul J. Wiedefeld said in an email press release. “Above all, I thank the thousands of riders who rely on our services every day. I know this temporary suspension of service has been an inconvenience for many of our customers, and I greatly appreciate their understanding.”

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MTA Administrator Holly Arnold and her team pulled the entire light rail fleet from service after an investigation into an Oct. 21 fire event revealed problems in the electrical system of the car in question. At the time, it was unclear how many other railcars, if any, of the 49 in service before the suspension had the same mechanical issue.

The 49 railcars in service at the time had already returned from major rehabilitation work conducted by a private rail company, Alstom. The “midlife overhaul” of the railcars, yet to be completed, has been installing new propulsion systems and other upgrades to help the vehicles reach the end of their useful lives.

The MTA’s online railcar progress tracker lists 14 vehicles as safety certified and ready for service starting Saturday. That means the MTA will be able to provide limited service. Arnold has said previously that 19 railcars are needed to return to full service. The entire fleet contains 53 railcars.

Repairs continue, with 13 additional railcars already getting at least one of two main fixes and awaiting safety certification. Ten railcars are awaiting work, and 12 have yet to have their conduits — the center of botched rehabilitation — inspected.

MTA also announced that it applied this week for $225 million in federal grants to put toward the purchase of new light railcars. Ranging from 24 to 31 years old, the entire light rail fleet has reached or is approaching the end of its useful lifespan of 30 years. The light rail first began service in 1992 in conjunction with the opening of Camden Yards.

Earlier this year, the MTA received the first of 78 new heavy railcars that will replace its aged Metro subway fleet.