Spanish firm Sistemas Integrales de Telecomunicacion (SIT) replaced the WRC's long-standing timing and tracking provider Stage One Technology for this year, but immediately hit problems.
The series opener in Monte Carlo was thrown into confusion when incorrect times were posted for competitors, split times were unavailable and cars were left untracked in the French Alps.
SIT promised an improvement in the service in Sweden, but Mahonen says he expects nothing less than operational perfection.
"They [SIT] will be doing their homework before Sweden," Mahonen told AUTOSPORT, "and we expect perfect service there. I will make my conclusion after that event.
"Monte Carlo was a difficult rally for the new supplier to come to, the terrain is very hard, so I think maybe it's unfair to say too much about that event.
"I think there was some breakdown in communication from SIT, but the tracking is vital. This is from the safety side and this is number one over all other [things]."
During Monte Carlo team personnel and competitors questioned the reason for the change of supplier from Stage One to SIT.
Second-placed Sebastien Ogier's co-driver Julien Ingrassia said: "There are simple things where we don't need a revolution and this is one of them..."
VW team principal Jost Capito labelled SIT's performance on the Monte Carlo Rally as "completely unacceptable and completely irresponsible."
Asked whether Stage One Technology would return to the WRC, the company's managing director Simon de Banke said: "We're working on a number of new projects right now, but the WRC is close to our hearts so we certainly wouldn't rule out further discussion."