NHTSA complaint #11549774

Owner complaint summary

The contact owns a 2020 Mercedes-Benz GLC63. The contact stated that while his wife was driving at highway speeds, the vehicle inadvertently decelerated while the accelerator pedal was being depressed. The check engine warning light illuminated, and a message displayed on the instrument panel stated that the “Transmission Needs to Cool, Stop and Pull Over Immediately”. The contact stated that the vehicle had locked in first gear and decelerated to approximately 55 MPH. Additionally, the contact stated that his wife was able to navigate the vehicle back to the residence. The contact stated that the following day the contact was able to restart the vehicle. The vehicle was taken to the dealer where it remained awaiting a diagnostic test. The vehicle had not yet been repaired. The manufacturer was notified of the failure and the contact was provided a case number. The failure mileage was approximately 24,000.