A faulty brake pedal sensor may cause your 2020 RAM 1500 not to start or may prevent the push button start from functioning. Symptoms of a malfunctioning brake pedal sensor include the brake lights not illuminating when the brake pedal is pressed or the vehicle not responding to the push button start when the brake pedal is depressed. If you suspect a faulty brake pedal sensor, consult with a professional mechanic for further diagnosis and replacement if necessary.