George Russell’s Monaco Grand Prix was undone in qualifying when his W16 lost power and coasted to a standstill in the tunnel, his session over with the driver languishing in 14th place.

Mercedes team representative Bradley Lord has revealed Mercedes have not only identified the issue, a wiring loom that short-circuited, but they’re also examining all the others engines in the pool to ensure there’s no repeat of the failure.

What caused George Russell’s loss of power in Monaco?

Inside the top five in Q1 at the Monaco Grand Prix, Russell went into Q2 chasing a spot inside the top ten pole position shoot-out.

He was the only Mercedes driver doing so having lost his team-mate Kimi Antonelli late in Q1 when the Italian crashed, bringing his Saturday running to a premature end.

However, Russell joined his team-mate on the sidelines when he coasted to a halt inside the tunnel to a cry of: “I’ve lost power!”

He tried to reset but nothing worked, and Mercedes told him it was “game over” as marshals hurried to push his stranded W16 out of the tunnel and out of the way.

Russell’s P14 starting position on the grid meant he spent the better part of the Grand Prix being held up as first Racing Bulls and then Williams backed up the field in a game of team-mate strategy. The Briton finished outside of the points in 11th, while Antonelli was the last of the classified runners in 18th place.

The good news is Mercedes have identified the cause of Russell’s qualifying troubles, and have taken steps to ensure that it won’t happen again.

F1 2025: The season’s winners and losers

👉 The results of the F1 2025 championship

👉 The updated Drivers’ and Constructors’ Championship standings

“Yeah, so, George, we’d made a lot of setup changes going into qualifying,” Lord began in the Mercedes’ debrief. “Having struggled a bit in the free practice sessions, George reported the car feeling much better and much more alive under him.

“So he was optimistic of fighting for the front two rows in qualifying, then got into his first run in Q2, through the first corner he’d already found a tenth of a second running on that Medium tyre. So, again, the performance indication was good.

“And then suddenly he lost power. He came on the radio, said, got no power, got no drive.

“It transpires that what has happened is that a wiring loom has short-circuited and that has cost ignition power to the combustion engine.

“So George, for the next part of the lap, was able to motor on the electric motor. So the MGU-K and draining down the energy that was in the battery. But then that also ran out in the tunnel.

“So ultimately, an electrical problem, a short circuit in a wiring loom that led to a failure of the ignition electrics on the engine.”

Having identified the cause of the problem, Lord revealed Mercedes will examine all of the other power units available to the drivers, and implement fixed if required as well as preventative measures.

“In terms of resolving that, we’ve been able to identify what’s happened,” he continued. “We’ll be able to countercheck all of the other PUs that are in the pool to make sure that there isn’t any imminent danger of a repeat.

“Apply any fixes that are required there and any preventative measures and then ensure that in the build processes going forward, that that particular point, which is something we haven’t seen before on this PU, is counter measured and prevented.”

Mercedes head into the Spanish Grand Prix, round nine of the F1 2025 championship, second in the Constructors’ standings where they trail runaway championship leaders McLaren by 172 points.

Russell in fourth on the Drivers’ log with 99 points, 62 behind Oscar Piastri, while Kimi Antonelli has 48 points to his tally

Read next: Zak Brown calls out rivals for ‘bogus allegations’ and ‘dishonest’ FIA protests