Limited control mode (Mondeo 1 and 2)

The petrol engine control system is equipped with a "limited controllability" program, which operates as follows.

If during the movement the BZU self-diagnostic system detects any malfunction of sensors, actuators or their circuits, the program starts looking for options to replace the faulty signal with something else to continue engine control. For example, if the engine temperature sensor fails, the program replaces it with a signal from the oil temperature sensor.

If there is no such sensor or it is also faulty, the system replaces the sensor signal with a constant value, which is stored in the ECU memory. This ECU function allows the car to continue moving, although with less efficiency. In any case, the car can be driven to a garage or the nearest service station. The driver is notified of the ECU switching to the limited control mode by a signal lamp.

It is recommended to search for and eliminate this type of malfunction with the help of specialists.