Tests have been carried out on the recently-installed signals and traffic lights along the route of Cambridgeshire's guided busway.
This is spite of the fact that Cambridgeshire County Council has yet to announce a definite date when the £116m scheme will open.
It is now likely that another contractor will be brought in to finish the defects on the guided sections.
Bob Menzies, who is in charge of delivering the busway for the council, said: "The way the contract works, the contractor has 28 days after completion to fix any defects.
"From all the discussions we've had with BAM Nuttall we've no expectations they're actually going to do that, so we're arranging with one of our other contractors, who does other work for the county council, to step in and fix these defects."