F1: FIA explains Sepang software bug ahead of Singapore

The FIA published on Thursday 8 October 2026 the findings of its investigation into the software bug at the Bahrain Grand Prix held in Sepang, Malaysia. The defect cost several cars power on the formation lap, before the start of this Formula 1 race was delayed. The report explains the cause and announces two measures, one of them for the upcoming Singapore Grand Prix.

What the FIA found

The review covered the precise cause of the power loss, measures to prevent a recurrence and the future management of wet-weather engine settings. Its conclusion: some cars running at low engine RPM in certain sectors of the circuit, where a 250kW power reduction was applied, lost more power than intended. They could not recover it in those sectors.

According to RaceFans, cars with Red Bull-Ford, Ferrari and Audi power units slowed sharply on the formation lap. The FIA says the software limits the power available at different points of the lap, a feature tied to the 2026 power unit rules.

Sunday's timeline

The FIA sets out the sequence of the intervention:

• 15:45: the start procedure is suspended after two formation laps;
• 15:50: the FIA technical team identifies the cause within five minutes and releases an updated software configuration;
• 16:03: teams receive further technical guidance;
• 16:20: teams and power unit manufacturers complete integration, with all competitors ready about 20 minutes later;
• 16:22: the 10-minute signal is given;
• 16:33: cars leave the pit lane for the start procedure.

Tested before the race, says the FIA

The FIA responds to comments suggesting the software had not been tested. Before deployment, teams and power unit manufacturers ran simulations. The software was then run in full-scale conditions during Free Practice 1 at the Belgian and Dutch Grands Prix. It does acknowledge that testing opportunities are limited and recommends strengthening testing and verification, with independent assessment and input from the supplier of the standardised ECU.

The measures announced

• Singapore: the Sepang configuration will be reinstated if similar weather is expected. According to RaceFans, the Singapore weekend is a sprint weekend with a single one-hour practice session, and no other changes are planned.
• United States: a further wet-weather software update will be released for the 25 October Grand Prix.

The FIA thanks the teams, power unit manufacturers and its technical staff for their responsiveness, which allowed the race to proceed safely.

Key takeaways

The FIA wants to strengthen testing and validation of power unit software, notably for wet weather. In Singapore, teams will return to the Sepang setting if the weather requires it, ahead of the update planned for the United States.