A malfunction of the electronic control unit (ECU) is indicated by the “Check Engine” sensor, and computer diagnostics will be required to clarify the problem. The main symptoms of a malfunctioning ECU are such engine problems as a failure, inability to start. Replacing the engine control unit begins with determining its location. Before removing the unit, disconnect the battery, disconnect the blocks with wires from the control unit, remove the device and install a new one. After that, check the operability of the electronic control unit. It may be required to adapt the device.