If at the beginning of the movement of the Mercedes E-Class (W212) shows red marks, then signals and switches off, this may indicate a failure of one of the sensors or the break-up of the circuit.
Before calling the service center, you need to clear the external surface of the sensors from the dirt. You have to be careful not to scratch the sensors. If the system does not recover from this, diagnostics and repair must be performed. Sometimes the normal operation of the parktroics may be impeded by various sources of ultrasound and radio-wave radiation.
