FIA details wet-weather software fix after Sepang race-start chaos
The FIA has completed its investigation into the power-loss incident that disrupted the opening phase of the race at Sepang, where several cars slowed dramatically behind the safety car. The governing body traced the problem to software linked to the 250kW power restrictions applied in wet conditions.
In its review, the FIA found that cars running at low engine speeds in certain circuit sectors subject to the reduction could suffer a loss of power greater than intended. That power could not be recovered within those sectors. The software issue placed the electric motors in a lock-down state at the slowest points, leaving drivers without electric power to compensate for turbo lag when they pressed the throttle.
The FIA issued an emergency software update before the restart. It lifted the 250kW restrictions in specific minisectors where the fault had appeared. The same temporary configuration will be reinstated for the Singapore Grand Prix if similar weather conditions are expected. A further update to the wet-weather software is scheduled for the United States Grand Prix on October 25.
The two-stage response means the Sepang fix will cover Singapore, while a revised software package is planned for Austin. The FIA’s explanation of the wet-weather software fault provides further detail on how the issue left cars without usable power.
Testing process under review
FIA single-seater director Nikolas Tombazis said after the race that the specific fault would not recur, while acknowledging that he could not rule out other problems in complex power-unit software. “This specific problem, yes. A problem, no. But we will do our best to avoid it, of course,” he said.
The FIA has now clarified that the software was tested during opening practice sessions at the Belgian and Dutch Grands Prix, but the fault did not emerge. The cars were running at normal speeds in those sessions, rather than reaching the extremely low speeds experienced behind the safety car at Sepang.
That difference has prompted a wider review of validation. The FIA said the investigation recommended measures to make software testing as robust as possible, while recognising that opportunities to test in wet conditions are limited. It will work with teams and power-unit manufacturers to strengthen testing and verification, including independent assessment and feedback from the supplier of the standardised electronics control unit.
The immediate remedy addresses the conditions that triggered the Sepang failure. The longer-term task is to improve validation so that software is tested against the less common operating situations that proved decisive in Malaysia.
Simone Scanu
He’s a software engineer with a deep passion for Formula 1 and motorsport. He co-founded Formula Live Pulse to make live telemetry and race insights accessible, visual, and easy to follow.