When the Mercedes Benz C new energy plug-in hybrid brake fails, one should remain calm, stabilize the steering wheel, and try to step on the brake pedal multiple times to see if the problem is caused by a temporary malfunction or jamming of the brake system.
If multiple brake presses are ineffective and the vehicle is equipped with a handbrake device, the handbrake should be slowly and steadily pulled up to attempt to slow down and stop. For vehicles equipped with electronic handbrakes, the electronic handbrake button can be continuously pulled up to achieve deceleration. Meanwhile, it is also possible to consider utilizing the vehicle's auxiliary braking system, such as engine braking.
If none of the above methods can solve the problem, immediately turn on the hazard warning flasher and sound the horn to alert surrounding vehicles. Subsequently, try to control the direction of the vehicle as much as possible, find a safe zone to slow down and stop, and promptly use the onboard communication system or mobile phone to contact rescue services. In case of last resort, the speed can be reduced by scraping against obstacles on the side of the vehicle, but frontal collisions should be avoided as much as possible to minimize losses and risks.