OC Transpo has pulled about a third of its fleet of double-decker buses off the road for repairs after a wire harness on one of them overheated.

Forty-three buses were grounded on Friday after a driver reported fumes on a bus Thursday night, OC Transpo director of transit operations Troy Charter said in a statement released by the city.

The fumes were caused by a wire harness on the bus overheating. The bus didn't catch fire and no one was at risk, Charter said.

"As a proactive measure, we contacted the manufacturer and we are proactively inspecting and replacing wiring harnesses that are affected," the statement said, adding that the work will be done this weekend.

The problem only affects the latest 43 double-deckers in the city's fleet. There are 117 double-decker buses in the fleet overall.

Charter said there will be some minor adjustments to bus service Friday evening, but no impact to bus service Monday morning.

Last week, an OC Transpo double-decker bus caught fire on an early-morning route in the southeast end.

OC Transpo said this latest problem is unrelated to that fire.

That bus had also experienced mechanical problems days earlier, on the previous Friday. It was taken off the road for repairs that weekend, then put back into service.