SEPTA has completed federally required inspections on all 223 Silverliner IV Regional Rail cars, meeting an extended deadline set by the Federal Railroad Administration after multiple fires were reported on the cars in recent months.

While the inspections are completed on time, there will still be impacts, and leaders admit it will be some time before the full fleet is back out on the tracks.

Now, all cars are being outfitted with thermal protection circuits, which have sensors that detect if a car is overheating. If those sensors go off, they can kill the power to that car, stopping the overheating and preventing fires before they happen.

SEPTA says in that case, the rest of the cars would power the train to the next stop, so it wouldn't just shut down on the tracks.

Engineers at SEPTA'S Overbrook Maintenance Facility showed CBS News Philadelphia how the system works.

"Anything on the car gets over 190 degrees, it'll short together, light that fault light, lower the pantograph to remove power from the train and also light a fault light in the operating cab," said Regional Rail Vehicle Engineering Manager Greg Buzby.

General Manager Scott Sauer said in a news conference at a maintenance shop that SEPTA should meet a Dec. 5 deadline to outfit all cars with those detectors. About 67 of these cars already have the detectors installed, with about five a day being outfitted and then released back into the system.

"We project it's probably going to take us another month as we build the fleet," Sauer said. "About mid-December is when we'll see the entire fleet back, ready to go."

Not the news riders were hoping to hear, but many say safety must come first.

"It's been difficult, but I appreciate the fact that they're trying to correct the problems with the train so that they're safe when we ride on them," said Dr. Linda Ziman of West Mount Airy.

Regional Rail trains will also have additional cars to use after SEPTA rented 10 from Maryland Area Rail Commuter to serve routes with cars out for service.

With dozens of cars out for repairs and inspections, SEPTA pre-canceled several Regional Rail train trips this week due to the lack of railcars available. Leaders will meet Sunday to discuss whether more pre-cancellations will be necessary for next week, and that will depend on the number of cars available for the system.

"This has been an extremely difficult time for our customers, and I will not make any promises about service improvements we cannot keep," Sauer said.

There have been between 87 and 120 cars riding on the system each day. If that number is on the low end, riders can expect some cancellations.