Clutch control unit issue led to Rasmussen retirement at Road America

A post-race investigation has revealed the end to Christian Rasmussen’s run on Sunday at Road America’s XPEL Grand Prix to be the result of something other than a failure of IndyCar’s spec hybrid system.

RACER has confirmed through the series that Rasmussen’s No. 21 ECR Chevy slowed and stopped at the start/finish line when the CCU – the Clutch Control Unit – failed, which it says affected the hybrid as collateral damage from the failing electronics.

Rasmussen was running ninth just prior to the CCU issue, pitted on lap 28, returned in 15th, but came up a few feet short of reaching lap 29 as his car crawled to a stop and sat locked in gear. Attempts to remove the No. 21 Chevy by flat-towing it away with Rasmussen in the car were unsuccessful; he was instructed to exit the car so it could be lifted off its wheels and returned to the paddock.

The misfortune for the 2023 Indy NXT champion added to a miserable run for the 25-year-old, who’s finished 24th or worse at four of the last five races. The lone highlight was produced at World Wide Technology Raceway where Rasmussen charged to a third-place finish, which stands as his best and ECR’s best result of the season. Despite that podium, the string of poor finishes has Rasmussen holding 22nd in the drivers’ standings.