OC Transpo pulled 43 double decker buses off the streets for precautionary reasons.
A driver noticed a smell of fumes on one of them last night.
They traced the smell to an overheated wiring harness.
There was no fire or risk posed to the public.
It was last week that a double decker was destroyed by fire, but OC Transpo says there is no connection.
After talking to the buses manufacturer, they decided to pull the buses and replace all of the wiring harnesses.
There will be a few minor disruptions to service, but it should be back to normal Monday.