UPDATE: Most TTC articulated buses fixed

TTC bus service is at full strength after crews worked through the night to repair Toronto's fleet of articulated buses.

153 of the 60-foot "accordion" buses were pulled off the road Thursday after what the TTC calls an "unexpected acceleration" during routine maintenance.

"Whether in drive or park, it would suddenly jackrabbit forward," explains TTC spokesperson Brad Ross.

He says there was a second incident as a driver was pulling a bus into the Malvern garage. There were no customers on board at the time and no one was injured.

The buses' manufacturer, Nova, had a software fix for the problem and TTC employees worked to apply it overnight.

Just before 7 a.m. Ross says 125 buses had been patched, the number needed for peak morning service. The TTC didn't anticipate any further service delays because of the glitch.

With files from Siobhan Morris