Charles Leclerc will use the same engine at the next race in China as the one that developed a problem that cost him victory in Bahrain on Sunday.
Ferrari said they had traced the issue that dropped Leclerc from first to third behind the two Mercedes to “a short circuit within an injection-system control unit”.
The team said they had never seen this problem before with that component.
Leclerc is fourth in the championship after the first two races of 2019.
The championship is led by Mercedes’ Valtteri Bottas, winner of the opening race in Australia, one point ahead of team-mate Lewis Hamilton, who inherited victory in Bahrain from Leclerc.
Red Bull’s Max Verstappen is third, 17 points behind Bottas and one ahead of Leclerc.
The 21-year-old Monegasque is four points ahead of team-mate Sebastian Vettel, and his performances have raised questions about Ferrari’s decision to give the German priority in the opening races of this season.
Leclerc was asked to back off and not pass Vettel as he caught him in the closing stages in Australia, and in Bahrain he was quicker than the four-time champion throughout the weekend.
Leclerc qualified on pole, 0.3 seconds ahead of Vettel, lost the lead at the start but caught and passed the German, ignoring a request from the team to hold station behind Vettel for two laps.
Vettel later spun while racing with Hamilton, the fourth time he has lost control of his car during an on-track battle in the past 10 races – and his fifth error in 13 including crashing out of the lead of his home grand prix last July.
Ferrari have yet to say how they will respond to Leclerc’s form.